Question 62419
E1:  7x-4y=40
E2:  y-x=2
Solve E2 for y and substitute that in for y in E1.
E2:  y-x+x=x+2 -->{{{y=highlight(x+2)}}}
E1:  {{{7x-4*highlight(x+2)=40}}}
7x-4x-8=40
3x-8=40
3x-8+8=40+8
3x=48
3x/3=48/3
x=16
Now substitue x=16 into E2 and solve for y.
y-16=2
y-16+16=2+16
y=18
The solutuion is (16,18)
Happy Calculating!!!