Question

BT: Rút gọn

a) \(x\)² -6\(xy\)+9x\(y\)² 

b) \(x\)³ +6\(x\)² \(y\)+12\(xy\)² +8\(y\)³ 

c) \(x\)² - 64

d) 125\(x\)³ + \(y\)6 

e) 0,125x (\(a\) +1)³ - 1                         

Answer 1

e: \(0,125\left(a+1\right)^3-1\)

\(=\left(0,5a+0,5\right)^3-1\)

\(=0,125a^3+0,375a^2+0,375a+0,125-1\)

\(=0,125a^3+0,375a^2+0,375a-0,875\)

a: \(x^2-6xy+9y^2=x^2-2\cdot x\cdot3y+\left(3y\right)^2=\left(x-3y\right)^2\)

b: \(x^3+6x^2y+12xy^2+8y^3\)

\(=x^3+3\cdot x^2\cdot2y+3\cdot x\cdot\left(2y\right)^2+\left(2y\right)^3\)

\(=\left(x+2y\right)^3\)

c: \(x^2-64=x^2-8^2=\left(x-8\right)\left(x+8\right)\)

d: \(125x^3+y^6=\left(5x\right)^3+\left(y^2\right)^2=\left(5x+y^2\right)\cdot\left(25x^2-5xy^2+y^4\right)\)