化简 ((n^2)/5+4)((2n^2)/3-7)

解答

化简

(\frac{n ^{2}}{5} + 4) (\frac{2 n ^{2}}{3} - 7)

\frac{( 20 + n ^{2} ) ( - 21 + 2 n ^{2} )}{15}

求解步骤

(\frac{n ^{2}}{5} + 4) (\frac{2 n ^{2}}{3} - 7)

合并

\frac{n ^{2}}{5} + 4 : \frac{20 + n ^{2}}{5}

= \frac{20 + n ^{2}}{5} (\frac{2 n ^{2}}{3} - 7)

使用分式法则:

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

= \frac{( 20 + n ^{2} ) ( \frac{2 n ^{2}}{3} - 7 )}{5}

化简

(20 + n^{2}) (\frac{2 n ^{2}}{3} - 7) : \frac{( 20 + n ^{2} ) ( - 21 + 2 n ^{2} )}{3}

= \frac{\frac{( 20 + n ^{2} ) ( - 21 + 2 n ^{2} )}{3}}{5}

使用分式法则:

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

= \frac{( 20 + n ^{2} ) ( - 21 + 2 n ^{2} )}{3 \cdot 5}

数字相乘:

3 \cdot 5 = 15

= \frac{( 20 + n ^{2} ) ( - 21 + 2 n ^{2} )}{15}

e x p an d (x + 1)^{3} (6 - x)^{2} 3 2 x + 1

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

e x p an d 3 (2 + 5)

e x p an d \frac{( ( 3 x - 1 ) ( x + 2 ) )}{3}

e x p an d A (- 4, 5) B (2, - 1)