Question

Answer 1

i) \(=\left(3x-4+4-x\right)^2=\left(2x\right)^2=4x^2\)

j) \(=\left(3a-1\right)^2+2\left(3a-1\right)\left(3a+1\right)+\left(3a+1\right)^2=\left(3a-1+3a+1\right)^2=\left(6a\right)^2=36a^2\)