Câu hỏi của Đỗ Lê Thảo Linh

Question

Rút gọn:  (2x+3)2  +(2x+5)2 - 2(2x+3) (2x+5)

TAPN · Accepted Answer

$\left(2x+3\right)^2+\left(2x+5\right)^2-2\left(2x+3\right)\left(2x+5\right)$

$=\left(2x+3\right)^2-2\left(2x+3\right)\left(2x+5\right)+\left(2x+5\right)^2$

$=\left[2x+3-\left(2x+5\right)\right]^2$

$=\left(2x+3-2x-5\right)^2$

$=\left(3-5\right)^2$

$=\left(-2\right)^2$

$=4$Câu trả lời: $\left(2x+3\right)^2+\left(2x+5\right)^2-2\left(2x+3\right)\left(2x+5\right)$

$=\left(2x+3\right)^2-2\left(2x+3\right)\left(2x+5\right)+\left(2x+5\right)^2$

$=\left[2x+3-\left(2x+5\right)\right]^2$

$=\left(2x+3-2x-5\right)^2$

$=\left(3-5\right)^2$

$=\left(-2\right)^2$

$=4$

Ly Hoàng · Answer

$\left(2x+3\right)^2+\left(2x+5\right)^2-2\left(2x+3\right)\left(2x+5\right)$

$=\left(2x+3\right)^2-2\left(2x+3\right)\left(2x+5\right)+\left(2x+5\right)^2$

$=\left[2x+3-\left(2x+5\right)\right]^2$

$=\left(2x+3-2x+5\right)^2$

$=\left(3-5\right)^2$

$=\left(-2\right)^2$

$=4$Câu trả lời: $\left(2x+3\right)^2+\left(2x+5\right)^2-2\left(2x+3\right)\left(2x+5\right)$

$=\left(2x+3\right)^2-2\left(2x+3\right)\left(2x+5\right)+\left(2x+5\right)^2$

$=\left[2x+3-\left(2x+5\right)\right]^2$

$=\left(2x+3-2x+5\right)^2$

$=\left(3-5\right)^2$

$=\left(-2\right)^2$

$=4$

Bài 3: Những hằng đẳng thức đáng nhớ