Question

Solve this equation with substitution method :-
x+5 = 3 (y+5)
x-5 = 7 (y-5)

Answer 1

From the first equation,
x+5 = 3(y+5)
x = 3y + 15 - 5
Now substitue x in the second equation with (3y +15 - 5).
x-5 = 7(y-5)
(3y+15-5) - 5 = 7(y-5)
3y +5 = 7y - 35
-4y = - 40
y = 10

Since y is 10, and x is (3y +15 - 5),
x = 30 + 15 - 5 = 40