Question

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

Answer 1

3x + 2y = 7
y = -3x + 11

Solve the system of equation using substitution.

Substitute the y in the first equation by its value presented in the 2nd equation.

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

Substitute x in the 2nd equation by its computed value. x = 5
y = -3x + 11
y = -3(5) + 11
y = -15 + 11
y = -4

x = 5 ; y = -4

Substitute x and y in the 1st equation with its corresponding values

3x + 2y = 7
3(5) + 2(-4) = 7
15 - 8 = 7
7 = 7