rationalizenumerator ((4-sqrt(x)))/((x-16))

解答

有理化分子

\frac{( 4 - x )}{( x - 16 )}

- \frac{1}{x + 4}

求解步骤

\frac{4 - x}{x - 16}

乘以共轭根式

\frac{4 + x}{4 + x}

= \frac{( 4 - x ) ( 4 + x )}{( x - 16 ) ( 4 + x )}

(4 - x) (4 + x) = 16 - x

= \frac{16 - x}{( x - 16 ) ( 4 + x )}

x - 16 = - (- x + 16)

= \frac{16 - x}{- ( x + 4 ) ( - x + 16 )}

整理后得

= - \frac{16 - x}{( 4 + x ) ( - x + 16 )}

约分:

16 - x

= - \frac{1}{x + 4}

so l v e f or x, 9^{x} = 4

s im pl i f y - 17

so l v e f or m, \frac{( 2 m ^{2} + 3 m - 5 )}{( m ^{2} + 4 m - 5 )} = 4

e x p an d cos (13 5^{\circ})

- 56/7