Answer:
x = 5/(10 - a - b)
Explanation:
Solve for x:
4 + 3 x - a x = 9 - 7 x + b x
Collect in terms of x:
x (3 - a) + 4 = 9 - 7 x + b x
Collect in terms of x:
x (3 - a) + 4 = x (b - 7) + 9
Subtract (b - 7) x + 4 from both sides:
x (10 - a - b) = 5
Divide both sides by 10 - a - b:
Answer: x = 5/(10 - a - b)