展开 48(x/3+y/3)(x/4-y/4)

解答

展开

48 (\frac{x}{3} + \frac{y}{3}) (\frac{x}{4} - \frac{y}{4})

4 x^{2} - 4 y^{2}

求解步骤

48 (\frac{x}{3} + \frac{y}{3}) (\frac{x}{4} - \frac{y}{4})

展开

48 (\frac{x}{3} + \frac{y}{3}) (\frac{x}{4} - \frac{y}{4}) : 48 \cdot \frac{x ^{2} - y ^{2}}{12}

= 48 \cdot \frac{x ^{2} - y ^{2}}{12}

使用分式法则:

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

= \frac{48 ( x ^{2} - y ^{2} )}{12}

数字相除:

\frac{48}{12} = 4

= 4 (x^{2} - y^{2})

使用分配律:

a (b - c) = ab - a c

4 (x^{2} - y^{2}) = 4 x^{2} - 4 y^{2}

= 4 x^{2} - 4 y^{2}

y = x^{3} - 3 x + 2

s im pl i f y (x + 2) (x^{2} + 7) (x^{2} - 9)

e x p an d \frac{1}{x ^{2} ( x ^{2} + a ^{2} )}

s im pl i f y (x y + z) (x y - z)

e x p an d (4 \cdot sin (6 \cdot π \cdot t) + cos (80 \cdot π \cdot t))^{2}