## Intermediate Algebra (6th Edition)

$(3x+2)^2 \ne 9x^2+4$ because the square of $3x+2$ is $9x^2+12x+4$.
RECALL: $(a+b)^2=a^2 + 2ab+b^2$ $(3x+2)^2$ does not equal $9x^2+4$ because the square of a binomial is a trinomial. Squaring the binomial gives: $(3x+2)^2 \\=(3x)^2+2(3x)(2)+2^2 \\=9x^2+12x+4$