化简 (x^2-12x+20)/(5x^2+25x-70)

解答

化简

\frac{x ^{2} - 12 x + 20}{5 x ^{2} + 25 x - 70}

\frac{x - 10}{5 ( x + 7 )}

求解步骤

\frac{x ^{2} - 12 x + 20}{5 x ^{2} + 25 x - 70}

因式分解

x^{2} - 12 x + 20 : (x - 2) (x - 10)

= \frac{( x - 2 ) ( x - 10 )}{5 x ^{2} + 25 x - 70}

因式分解

5 x^{2} + 25 x - 70 : 5 (x - 2) (x + 7)

= \frac{( x - 2 ) ( x - 10 )}{5 ( x - 2 ) ( x + 7 )}

约分:

x - 2

= \frac{x - 10}{5 ( x + 7 )}

s im pl i f y - 5 \cdot - 5

s im pl i f y 3 \times \frac{3}{2}

s im pl i f y \frac{52 !}{5 ! 47 !}

s im pl i f y 71

e x p an d (2 x^{2} - 3 x + 4) (3 x^{2} + 2 x - 3)