2x + 3y = 9
3x - y = 8

Answer:

First, round $19.83 to make the mental math easier.  Then round the tip as well.  Then you can easily multiply the two rounded numbers to find the value.

Step-by-step explanation:

Answer:

-13h - 12

Step-by-step explanation:

3(-6h - 4) + 5h

-18h - 12 + 5h

-13h - 12

hope this helps! :D

have a miraculous day, and brainliest is immensely appreciated!! <3

Answer:

30

Step-by-step explanation:

4(3)^2 +(3*-2)

4*9-6=36-6=30

Answer:

30

Step-by-step explanation:

Substitute x = 3 and y = - 2 into the expression

4x² + xy

= 4(3)² + 3(- 2)

= 4(9) - 6

= 36 - 6

= 30

Answer:

12, 63 and 21 sum to 96

.....

x+(-2) >3

open the bracket

x-2>3

collect the like terms by taking 2 to the other side

x>3+2

x>6

Answer:

It is an identity, proved below.

Step-by-step explanation:

I assume you want to prove the identity. There are several ways to prove the identity but here I will prove using one of method.

First, we have to know what cot and cosec are. They both are the reciprocal of sin (cosec) and tan (cot).

[tex]\displaystyle \large{\cot x=\frac{1}{\tan x}}\\\displaystyle \large{\csc x=\frac{1}{\sin x}}[/tex]

csc is mostly written which is cosec, first we have to write in 1/tan and 1/sin form.

[tex]\displaystyle \large{1+(\frac{1}{\tan x})^2=(\frac{1}{\sin x})^2}\\\displaystyle \large{1+\frac{1}{\tan^2x}=\frac{1}{\sin^2x}}[/tex]

Another identity is:

[tex]\displaystyle \large{\tan x=\frac{\sin x}{\cos x}}[/tex]

Therefore:

[tex]\displaystyle \large{1+\frac{1}{(\frac{\sin x}{\cos x})^2}=\frac{1}{\sin^2x}}\\\displaystyle \large{1+\frac{1}{\frac{\sin^2x}{\cos^2x}}=\frac{1}{\sin^2x}}\\\displaystyle \large{1+\frac{\cos^2x}{\sin^2x}=\frac{1}{\sin^2x}}[/tex]

Now this is easier to prove because of same denominator, next step is to multiply 1 by sin^2x with denominator and numerator.

[tex]\displaystyle \large{\frac{\sin^2x}{\sin^2x}+\frac{\cos^2x}{\sin^2x}=\frac{1}{\sin^2x}}\\\displaystyle \large{\frac{\sin^2x+\cos^2x}{\sin^2x}=\frac{1}{\sin^2x}[/tex]

Another identity:

[tex]\displaystyle \large{\sin^2x+\cos^2x=1}[/tex]

Therefore:

[tex]\displaystyle \large{\frac{\sin^2x+\cos^2x}{\sin^2x}=\frac{1}{\sin^2x}\longrightarrow \boxed{ \frac{1}{\sin^2x}={\frac{1}{\sin^2x}}}[/tex]

Hence proved, this is proof by using identity helping to find the specific identity.

Answer:

36.19047619 million

or 36,190,476 students

Step-by-step explanation:

7.6 million / all students = 21% / 100%

7.6 * 100 / 21 = 36.19047619

36.19047619 million

or 36,190,476 students

Im good at math, what do you need help with?

Answer:

what grade are u in so I know

Answer:

1   7/16

Step-by-step explanation:

Answer:

Statement 1 is true; Statement 2 is false.

Step-by-step explanation:

Statement 1:

√12 - √8 = a

Let's use the given value of √12 + √8 ,that is, 4/ a.

If we multiply both the expressions such that their Left Hand Sides get multiplies together and Right Hand Sides together:

=> (√12- √8)(√12 + √8) = a × 4/a

On the LHS,

identity used:

(a-b)(a+b) = a²-b²

On the RHS:

a gets canceled due to its presence in both the numerator as well as the denominator.

=> 12 - 8 = 4

=> 4 = 4

That's it!

We got LHS = RHS, that approves the existence of the given statement.

___________________

Statement 2:

"a + √b is called the rationalizing factor of c + √d if their product is 1"

That's not entirely right!

The correct statement would be:

" a + √b is called the rationalizing factor of c + √d if their product is a rational number ."

Since, rationalizing has got nothing to do with 1, (1 is just another rational number), even if we get 2 by their multiplication, it will be called rationalizing as long as we're getting a rational number.

___________________

Answer:

Hence, I'd say:

Statement 1 is correct but Statement 2 isn't.

That's the third option.

Step-by-step explanation:

$103.23

$100

$45.34

+_____

=248.57

Answer:

1712 square meters

Step-by-step explanation:

2000 - 288 = 1712

Answer:

[tex]\left(h,\:k\right)=\left(-\frac{3}{2},\:\frac{9}{4}\right),\:p=-\frac{1}{4}[/tex]

Step-by-step explanation:

[tex]x^2+3x+y=0[/tex]

[tex]4\left\bigg(-\frac{1}{4}\right)\left\bigg(y-\frac{9}{4}\right)=\left\bigg(x-\left\bigg(-\frac{3}{2}\right)\right)^2[/tex]

[tex]\bold{\mathrm{Therefore\:parabola\:properties\:are:}}[/tex]

[tex]\left(h,\:k\right)=\left(-\frac{3}{2},\:\frac{9}{4}\right),\:p=-\frac{1}{4}[/tex]

Answer:

  1. 125 cm³; 88.8 cm³; 1650 cm³; 0.11 m³

  2. about 1.47 kg

  3. can't tell what the volume of 1 jar is

Step-by-step explanation:

The relationship between volume, mass, and density is ...

  mass = volume × density

Solving for volume, we find ...

  volume = mass ÷ density

__

(a) 50 g/(0.4 g/cm³) = 125 cm³

(b) 770 g/(8.67 g/cm³) ≈ 88.8 cm³ . . . (rounded to 3 significant figures)

(c) 4000 g/(2.42 g/cm³) ≈ 1650 cm³ . . . (rounded to 3 significant figures)

(d) 80 kg/(720 kg/m³) ≈ 0.11 m³ . . . (rounded to 2 significant figures)

_____

The volume of the cylinder is ...

  V = πr²h

  V = π(4 cm)²(15 cm) = 240π cm³ ≈ 754.0 cm³

Using the above relation, we find the mass to be ...

  mass = (754.0 cm³)(1.95 g/cm³) ≈ 1470 g = 1.47 kg

_____

We cannot tell if the volume of each jar is 360 liters, or if that is the total volume of all 6 jars. Either way, we suspect a units problem, as the jars would have to be extremely large and unusually thin relative to what we usually think of as a jar for jam (0.77 m diameter; 0.2 mm thick). The density of the jam would be roughly 10 times the density of air, if that is the volume of all 6 jars. The problem would be more sensible if the units of volume were mm³, and the given volume is that of one jar.

The mass of jam in one jar is (5400/6 -200) = 700 g. Divide that by what you think the volume of one jar is in cm³ to find the density in g/cm³. (For comparison, the density of air is about 0.0012 g/cm³.)

_____

Additional comment

We have rounded the answers to 2 or 3 significant figures. In most cases, this is more than would be justified by the number of significant figures in the given measurements. For purposes of ongoing calculations, it is useful to keep intermediate results to at least 1 more significant figure than required for the answer.

Answer:

Step-by-step explanation:

1. 3 cans cost 90 cents

3=0.90 & x=2.7

by ratio:

3/0.9 = x/2.7

0.9x=8.1

x= 9

So you can buy 9 cans for 2.7 dollars

2. 10 Juice cost 3 dollars

by ratio:

10/3 = 4/x

10x=12

x=1.2

so you will spend 1.2 dollars to buy 4 juice packs

Answer:

(i) 4000

(ii) $5.00

Step-by-step explanation:

Let no. of shares of Company A be X

Let share price of Company B on Day 7 be $y

Share price of Company B on Day 12 = $(y-0.50)

(i)

Consider Day 7:

4.60x - 2000y = 7400................ (1)

Consider Day 12:

4.80x - 5000(y-0.50) = -5800

4.80x - 5000y + 2500 = -5800

4.80x - 5000y = -8300............... (2)

(1)*2.5:

11.5x - 5000y = 18500................. (3)

(3)-(2):

11.5x - 4.80x - 5000y + 5000y = 18500 + 8300

6.70x = 26800

x = 4000

(ii)

Sub. x = 4000 into (1):

4.60(4000) - 2000y = 7400

-2000y = 7400 - 18400

-2000y = -11000

y = 5.5

Share price of Company B on Day 12

= 5.50 - 0.50

= $5.00

Answer:

₹4000

Step-by-step explanation:

₹800/10 books

₹80/1 book

(₹80/1 book)*(50) = ₹4000

Answer:

a equals  and b equals 7

Step-by-step explanation

divide both side by 3 getting a+b=(28/3)

subtract b from both sides getting a=(28/3)-b

to solve for b its the same way so b=(28/3)-a

you can then substitute

[tex]x^2+12x+35\\\\=x^2 +5x +7x +35\\\\=x(x+5) +7(x+5)\\\\=(x+7)(x+5)\\\\\\3x+15 = 3(x+5)[/tex]

Answer:

  (40, 6000) = 6000 sheets folded in 40 minutes

Step-by-step explanation:

Each point on the graph represents ...

  (minutes, sheets folded)

The point (40, 6000) represents that the machine can produce 6000 sheets folded in 40 minutes.

Answer:

$156.63

Step-by-step explanation:

223.75 - (223.75 x .3) = 156.625

Answer:

160 servings

Step-by-step explanation:

Step One:

1 gallon=16 cups

1 cup=10 servings

Step Two:

Multiply 16 by 10

which gives you your answer 160