化简 1/(x+4)+7/x

解答

化简

\frac{1}{x + 4} + \frac{7}{x}

\frac{8 x + 28}{x ( x + 4 )}

求解步骤

\frac{1}{x + 4} + \frac{7}{x}

x + 4, x

的最小公倍数:

x (x + 4)

根据最小公倍数调整分式

= \frac{x}{x ( x + 4 )} + \frac{7 ( x + 4 )}{x ( x + 4 )}

使用分式法则:

\frac{a}{c} + \frac{b}{c} = \frac{a + b}{c}

= \frac{x + 7 ( x + 4 )}{x ( x + 4 )}

化简

x + 7 (x + 4) : 8 x + 28

= \frac{8 x + 28}{x ( x + 4 )}

s im pl i f y lo g_{2} (\frac{1}{2 ^{2}})

s im pl i f y \frac{r s ^{5} t ^{3}}{r ^{4} s ^{4} t ^{- 2}}

f a c t or a^{3} (a - b + 1) - b^{2} (a - b + 1)

f a c t or 15 x^{2} + 22 x + 8

s im pl i f y (0.2 a + 8) (0.2 - 8)