please beo me solve the equation substitution

Answer:
[tex]\left \{ {{x=3} \atop {y=-4}} \right.[/tex]
Step-by-step explanation:
[tex]\left \{ {{5x + 2y =7} \atop {4x + y =8}} \right.[/tex]
[tex]\left \{ {{5x + 2y = 7} \atop {2(4x + y) = 8 x 2}} \right.[/tex]
[tex]\left \{ {{5x + 2y = 7} \atop {8x + 2y = 16}} \right.[/tex]
5x + 2y - (8x +2y) = 7 - 16
5x + 2y - 8x +2y = 7 - 16
5x - 8x = 7 - 16
x= 3
5 × 3 + 2y = 7
y = -4