Solve the linear system1).5x + 4y = 16
y = -16

2). 3x + 6y = 15
-2x + 3y = -3

3). 7y = -14x + 42
7y = 14 x + 14

Answers

Answer 1

Answer: 1.5x+4y=16
5x+4(-16)=16
5x-64=16
5x=80
x=16

2.3x+6y=15
-2x+3y=-3

Multiply the 2nd equation by 2

3x+6y=15
-4x+6y=-6
7x=9
x=9/7

3x+6y=15
3(9/7)+6y=15
27/7+6y=15
6y=78/7
y=78/42 or 39/21 or 13/7

3.7y = -14x + 42
7y = 14 x + 14

-14x+42=14x+14
-28x=-28
x=1

Answer 2

Answer: $1)\n \n\begin{cases} 5x + 4y = 16 \n y=-16\end{cases} \n \n \begin{cases} 5x + 4*(-16) = 16 \n y=-16\end{cases} \n \n \begin{cases} 5x -64 = 16 \n y=-16\end{cases}$

$\begin{cases} 5x = 16 +64\n y=-16\end{cases} \n \n \begin{cases} 5x =80/:5 \ \n y=-16\end{cases} \n \n \begin{cases} 5x = 16 +64\n y=-16\end{cases} \n \n \begin{cases} x =16\n y=-16\end{cases}$

$2)\n \n\begin{cases} 3x+6y=15 \n -2x + 3y = -3 \end{cases} \n \n\begin{cases} 3x = 15-6y \ /:3 \n -2x + 3y = -3 \end{cases} \n \n \begin{cases} x = 5-2y \n -2*(5-2y) + 3y = -3 \end{cases} \n \n\begin{cases} x = 5-2y \n -10+4y + 3y = -3 \end{cases} \n \n$

$\begin{cases} x = 5-2y \n 7y = -3+10 \end{cases} \n \n \begin{cases} x = 5-2y \n 7y = 7 \ /:7\end{cases} \n \n \begin{cases} x = 5-2 *1 \n y =1 \end{cases} \n \n \begin{cases} x = 3 \n y = 1 \end{cases} \n \n$

$3)\n \n\begin{cases} 7y = -14x + 42 \n 7y = 14 x + 14 /:7 \end{cases} \n \n\begin{cases} 7*(2x+2) = -14x + 42 \n y = 2 x + 2 \end{cases} \n \n \begin{cases} 14x+14 = -14x + 42 \n y = 2 x + 2\end{cases} \n \n \begin{cases} 14x+ 14x = 42 -14 \n y = 2 x + 2 \end{cases}$

$\begin{cases} 28x = 28 \ /:28 \n y = 2 x + 2 \end{cases}\n \n\begin{cases} x = 1 \n y = 2 *1+ 2\end{cases}\n \n\begin{cases} x = 1 \n y = 4 \end{cases}$

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Evaluate the expression when x = 2

Answers

the answer is 1 when x=2

Explain how one whole, one tenth, and one hundredth are related.

Answers

They all consist of 1's, 0's, and decimal points.

Forty-five percent of the 300 shoppers in a supermarket bought milk. How many of the shoppers in a supermarket bought milk?

Answers

Turn 45% into a decimal. You get 0.45, because you move the decimal two places to the left.

Then multiply 300*0.45
You get 135

135 Shoppers in the supermarket bought milk.

solve the equation if 0 degrees is less than or equal to x which is less than or equal to 360 degrees. cos x= -1/2

Answers

Answer:

x = {120°, 240°}

Step-by-step explanation:

cos x = -1/2 for 0 ≤ x ≤ 360°

That cosine of x = -1/2 tells us two things immediately: 1) the hypotenuse has length 2 and the side adjacent to the angle x is -1. To have a negative adjacent side, angle x must be in either Quadrant II or Quadrant III.

If in Quadrant II, the terminal side of angle x is 30° past 90°, which means that x = 120°. If in Quadrant III, the terminal side of x is 30° short of 270°, which means that x = 240°

Then x = {120°, 240°}

A store sells packages of 48 Snickers bars for $28 per package, and packages of 36 KitKat bars for $22.50 per package. Mrs. Sweettooth bought some packages of Snickers bars and some packages of KitKat bars in this store. She bought total 204 candy bars and paid $123.50. How many of each brand of candy bars did she buy?

Answers

The number of Snickers bar and KitKat bar bought is 95 and 109 respectively.

How to solve an equation

Cost of 48 Snickers = $28

Cost per one = $28/48

= $0.583

Cost of 36 KitKat = $22.50

cost per one = $22.50/36

= $0.625

let

number of Snickers = x
number of KitKat = y

x + y = 204 (1)

0.583x + 0.625y = 123.50 (2)

From (1)

x = 204 - y

substitute into (2)

0.583x + 0.625y = 123.50

0.583(204 - y) + 0.625y = 123.50

118.932 - 0.583y + 0.625y = 123.50

- 0.583y + 0.625y = 123.50 - 118.932

0.042y = 4.568

y = 4.568/0.042

y = 108.761904761904

Approximately,

y = 109

substitute into (1)

x + y = 204

x + 109 = 204

x = 204 - 109

x = 95

Learn more about equation:

brainly.com/question/16863577

Answer: 96 snickers and 108 kitkats

Step-by-step explanation: you should do system of equations and then it would be 48s+36k=204 and 28s+22.5k=123.5, after you do the math, the answer turns out to be 96 snickers and 108 kitkats. :)

How do you solve 12.42 ÷ 4.6? I have a test tomorrow