10 câu Trắc nghiệm Toán 8 Bài 3: Những hằng đẳng thức đáng nhớ có đáp án (Nhận biết)

(A – B)(A + B) = A² + 2AB + B²

(A + B)(A – B) = A² – B²

(A + B)(A – B) = A² – 2AB + B²

(A + B)(A – B) = A² + B²

(x + y)² = (x + y)(x + y)

x² – y² = (x + y)(x – y)

(-x – y)² = (-x)² – 2(-x)y + y²

(x + y)(x + y) = y² – x²

(x + 2y)² = x² + 4xy + 4y²

(x – 2y)² = x² – 4xy + 4y²

(x – 2y)² = x² – 4y²

(x – 2y)(x + 2y) = x² – 4y²

(4x – 5y)(4x + 5y)

(4x – 25y)(4x + 25y)

(2x – 5y)(2x + 5y)

(2x – 5y)²

$(\frac{x}{9}-\frac{y}{64})(\frac{x}{9}+\frac{y}{64})$

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

$(\frac{x}{9}-\frac{y}{8})(\frac{x}{9}+\frac{y}{8})$

$(\frac{x}{3}-\frac{y}{8})(\frac{x}{3}+\frac{y}{8})$

9x² – 24xy + 16y²

9x² – 12xy + 16y²

9x² – 24xy + 4y²

9x² – 6xy + 16y²

$\frac{x^2}{4}-xy+4y^2$

$\frac{x^2}{4}-2xy+4y^2$

$\frac{x^2}{4}-2xy+2y^2$

$\frac{x^2}{2}-2xy+2y^2$

$(\frac{1}{4}xy+1{)}^2$

$(\frac{1}{2}xy+1{)}^2$

$(xy-\frac{1}{2}{)}^2$

$(\frac{1}{2}xy-1{)}^2$

(5x – 2y)²

(2x – 5y)²

(25x – 4y)²

(5x + 2y)²