2020 · Q30
If ab + xy − xb = 0 and bc + yz − cy = 0, then what is x/a + c/z equal to?
Elementary MathematicsAlgebra
- Ay/b
- Bb/y
- C1
- D0
Explanation
From ab+xy-xb = 0 we get x = ab/(b-y); from bc+yz-cy = 0 we get z = c(y-b)/y. Then x/a + c/z = b/(b-y) + y/(y-b) = 1. Hence option (C).