Solve by Substitution
Answer:
x = -5
y = -2
You said ax + 3b = 2f
Subtract 3b from each side: ax = 2f - 3b
Divide each side by 'a' : x = (2f - 3b) / a
15 + 2x - 4 = 9x + 11 - 7x
2x + 11 = 2x + 11
always true
2x + 3(4x - 1) = 2(5x + 3) + 4x
2x + 12x - 3 = 10x + 6 + 4x
14x - 3 = 14x + 6
never true
In an equation the Left hand side must equal the right hand side
4(5y-8-2)=185-15
20y-32-8=170
20y=170+32+8
20y=210
Therefore y=10,5
When you substitute the 10,5 and solve it on the left and side it's equal to 170 which is the answer on the right hand side
