Question

Simplify completely x2+4x-5 . 20x-12
-------- -------
5x2-8x+3 x2-6x-55

Answer 1

x^2 + 4x - 5 = (x + 5)(x - 1)
20x - 12 = 4(5x - 3)
5x^2 - 8x + 3 = (5x - 3)(x - 1)
x^2 - 6x - 55 = (x - 11)(x + 5)

when we write in fractions
(x+5)(x-1)*4(5x-3) / (5x - 3)(x -1)(x -11)(x +5)
all gets cancelled and we get
4/(x-11)

Answer 2

thank you!! :)

Answer 3

Factor all quadratics
\[\frac{x^2+4x-5 }{ 5x^2-8x+3 }\frac{20x-12}{ x^2-6x-55}\]
\[\frac{(x-1)(x+5) }{ (x-1)(5x-3) }\frac{4(5x-3)}{ (x-11)(x+5)}\]
\[\frac{\cancel{(x-1)}\cancel{(x+5)} }{ \cancel{ (x-1)}\cancel{(5x-3)} }\frac{4\cancel{(5x-3)}}{ (x-11)\cancel{(x+5)}}\]
\[\frac{4}{x-11}\]

Answer 4

thanks sam! :)