展开 ,A(2, 3/4)yB(3/5 ,-1/2)y

解答

展开

, A (2, \frac{3}{4}) y B (\frac{3}{5}, - \frac{1}{2}) y

+, \frac{3}{5} (2 \cdot \frac{3}{4},) A yy B, -, \frac{1}{2} (2 \cdot \frac{3}{4},) A yy B

求解步骤

, A (2, \frac{3}{4}) y B (\frac{3}{5}, - \frac{1}{2}) y

=, (2 \cdot \frac{3}{4},) (\frac{3}{5}, - \frac{1}{2}) A yy B

使用分配律:

a (b - c) = ab - a c

a = +, A (2, \frac{3}{4}) y B y, b = \frac{3}{5},, c = \frac{1}{2}

= +, A (2, \frac{3}{4}) y B y \frac{3}{5}, -, A (2, \frac{3}{4}) y B y \frac{1}{2}

= +, \frac{3}{5} (2 \cdot \frac{3}{4},) A yy B, -, \frac{1}{2} (2 \cdot \frac{3}{4},) A yy B

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

e x p an d \frac{54 e ^{x} ( - e ^{x} + 2 )}{( 3 e ^{x} + 6 ) ^{3}}

e x p an d lo g_{10} (3 x y) z^{11}

e x p an d \frac{2 ( 1 - 13 )}{3}

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