Question

Identify and correct the error shown in finding the

solution of:

`\left \{ {{3x-4y=14} \atop {x+y=-7}} \right.`
using substitution.

Answer 1

Explanation:

To solve using substitution

3x - 4y = 14

x + y = 7

First solve for y

y = -x + 7

then subsitute 3x - 4(-x-7) = 14

3x + 4x + 28 = 14

7x = 14 - 28

7x = -14

x = -2

Solve for y

-2 + y = -7

y = -7 + 2

y = -5