Question

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

Answer 1

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)