[tex]4y=2x-10[/tex] and [tex]y=6[/tex]
use the second expression to calculate the left-hand side of the first equation:
[tex]4\cdot 6 = 2x -10\\24 = 2x -10[/tex]
Add 10 to both sides if this equation to get
[tex]34 = 2x[/tex]
and divide both sides by 2
[tex]17 = x[/tex]
this proves that x = 17, give the two initial equations
