展开 ((80-x)*x)/4

解答

展开

\frac{( 80 - x ) \cdot x}{4}

- \frac{x ^{2}}{4} + 20 x

求解步骤

\frac{( 80 - x ) x}{4}

乘开

(80 - x) x : 80 x - x^{2}

= \frac{80 x - x ^{2}}{4}

使用分式法则:

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

\frac{80 x - x ^{2}}{4} = \frac{80 x}{4} - \frac{x ^{2}}{4}

= \frac{80 x}{4} - \frac{x ^{2}}{4}

数字相除:

\frac{80}{4} = 20

= 20 x - \frac{x ^{2}}{4}

改写为标准形式

= - \frac{x ^{2}}{4} + 20 x

e x p an d (3 sin (π x) - 2 sin (5 π x)) sin (\frac{nπ x}{20})

s im pl i f y 2 (x + y i)^{2}

e x p an d \frac{z + 16}{z ^{2} ( z - 1 )}

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

e x p an d \frac{x ( s + 12 )}{s ^{2} + 12 s + 36}