Câu 1:(x+1/3)^2 Câu2: ( 2x +y^2)^3 Câu3: (1/2x^2 +1/4y)^3 Câu 4: (3x^2 -2y)^3 Câu 5: (2/3x^2 -1/2y)^3 02/08/2021 Bởi Madelyn Câu 1:(x+1/3)^2 Câu2: ( 2x +y^2)^3 Câu3: (1/2x^2 +1/4y)^3 Câu 4: (3x^2 -2y)^3 Câu 5: (2/3x^2 -1/2y)^3
Đáp án+giải thích các bước giải: C1: (x+$\dfrac{1}{3}$)²=x²+2.x.$\dfrac{1}{3}$+ ($\dfrac{1}{3}$)² =x²+ $\dfrac{2}{3}$ + $\dfrac{1}{9}$ C2: (2x+y²)³=(2x)³+3.(2x)².y²+ 3.2x.$y^{4}$+$y^{6}$ =8x³+12x²y²+6x$y^{4}$+ $y^{6}$ C3: ($\dfrac{1}{2}$x²+ $\dfrac{1}{4}$y)³= ($\dfrac{1}{2}$x²)³ + 3.($\dfrac{1}{2}$x²)². $\dfrac{1}{4}$y + 3.$\dfrac{1}{2}$x².($\dfrac{1}{4}$)²+ ($\dfrac{1}{4}$)³ C4: (3x²-2y)³= (3x²)³-3.(3x²)².2y+ 3.3x².(2y)²- (2y)³ =27$x^{6}$- 54$x^{4}$y+ 36x²y²-8y³ C5: ($\dfrac{2}{3}$x²-$\dfrac{1}{2}$y)³= ($\dfrac{2}{3}$x²)³- 3.($\dfrac{2}{3}$x²)². $\dfrac{1}{2}$y+ 3.$\dfrac{2}{3}$x². ($\dfrac{1}{2}$y)² + ($\dfrac{1}{2}$y)³ =$\dfrac{8}{27}$$x^{6}$- $\dfrac{2}{3}$$x^{4}$y + $\dfrac{1}{2}$x²y²+ $\dfrac{1}{8}$y³ Bình luận
Đáp án+giải thích các bước giải:
C1:
(x+$\dfrac{1}{3}$)²=x²+2.x.$\dfrac{1}{3}$+ ($\dfrac{1}{3}$)²
=x²+ $\dfrac{2}{3}$ + $\dfrac{1}{9}$
C2:
(2x+y²)³=(2x)³+3.(2x)².y²+ 3.2x.$y^{4}$+$y^{6}$
=8x³+12x²y²+6x$y^{4}$+ $y^{6}$
C3:
($\dfrac{1}{2}$x²+ $\dfrac{1}{4}$y)³= ($\dfrac{1}{2}$x²)³ + 3.($\dfrac{1}{2}$x²)². $\dfrac{1}{4}$y + 3.$\dfrac{1}{2}$x².($\dfrac{1}{4}$)²+ ($\dfrac{1}{4}$)³
C4:
(3x²-2y)³= (3x²)³-3.(3x²)².2y+ 3.3x².(2y)²- (2y)³
=27$x^{6}$- 54$x^{4}$y+ 36x²y²-8y³
C5:
($\dfrac{2}{3}$x²-$\dfrac{1}{2}$y)³= ($\dfrac{2}{3}$x²)³- 3.($\dfrac{2}{3}$x²)². $\dfrac{1}{2}$y+ 3.$\dfrac{2}{3}$x². ($\dfrac{1}{2}$y)² + ($\dfrac{1}{2}$y)³
=$\dfrac{8}{27}$$x^{6}$- $\dfrac{2}{3}$$x^{4}$y + $\dfrac{1}{2}$x²y²+ $\dfrac{1}{8}$y³