Question

thu gọn:

a. (3x -1)² + (3x + 1)² + 2(3x + 1)(1-3x)

b. (2x - 3y)² + (2x + 3y)² + (2x -3y)(2x + 3y)

giúp mình với ạ, mình cảm ơn nhiều !!!

Answer 1

a ) \(\left(3x-1\right)^2+\left(3x+1\right)^2+2\left(3x+1\right)\left(1-3x\right)\)

\(=\left(1-3x\right)^2+\left(3x+1\right)^2+2\left(3x+1\right)\left(1-3x\right)\)

\(=\left(1-3x+3x+1\right)^2\)

\(=2^2=4\)

b ) \(\left(2x-3y\right)^2+\left(2x+3y\right)^2+\left(2x-3y\right)\left(2x+3y\right)\)

\(=4x^2-12xy+9y^2+4x^2+12xy+9y^2+4x^2-9y^2\)

\(=\left(4x^2+4x^2+4x^2\right)+\left(9y^2+9y^2-9y^2\right)+\left(12xy-12xy\right)\)

\(=12x^2+9y^2\)