3 years ago

Solve the system of equations using substitution. 3x + 2y = 7 y = –3x + 11

1 answer:

4 0

3x + 2y = 7
y = –3x + 11

replace y = –3x + 11 into 3x + 2y = 7

3x + 2y = 7
3x + 2(–3x + 11) = 7
3x -6x + 22 = 7
-3x = 7 - 22
-3x = -15
x = 5

y = –3x + 11
y = -3(5) + 11
y = -15 + 11
y = -4

x = 5 and y = -4

answer: D. (5, –4)

You might be interested in

-5x+2y=6 -x+2y=-2 what is the solution to the system of equations?

dybincka [34]

Step-by-step explanation:

$- 5x + 2y = 6 \\ - x + 2y = - 2 \\ \\ - 5x + 2y - ( - x + 2y) = 6 - ( - 2) \\ - 5x + 2y + x - 2y = 6 + 2 \\ - 4x = 8 \\ \frac{ - 4x}{ - 4} = \frac{8}{ - 4 } \\ x = (- 2) \\ \\ -5x + 2y = 6 \\ - 5 \times - 2 + 2y = 6 \\ 10 + 2y = 6 \\ 2y = 6 - 10 \\ 2y = - 4 \\ \frac{2y}{2} = \frac{ - 4}{2} \\ y = - 2 \\ now \: lets \: see \: whether \\ this \: equation \: is \: correct. \\ - x + 2y = - 2 \\ - ( - 2) + 2 \times - 2 = - 2 \\ 2 + 2 \times - 2 = - 2 \\ 2 - 4 = - 2 \\ - 2 = - 2 \\ yes \: this \: equation \: is \\ correct.$