Question

Please beo me solve the equation substitution

Answer 1

`\left \{ {{x=3} \atop {y=-4}} \right.`

Explanation:

`\left \{ {{5x + 2y =7} \atop {4x + y =8}} \right.`

`\left \{ {{5x + 2y = 7} \atop {2(4x + y) = 8 x 2}} \right.`

`\left \{ {{5x + 2y = 7} \atop {8x + 2y = 16}} \right.`

5x + 2y - (8x +2y) = 7 - 16

5x + 2y - 8x +2y = 7 - 16

5x - 8x = 7 - 16

x= 3

5 × 3 + 2y = 7

y = -4