Question

find the product of (2y-3z) (2y-3z) ​

Answer 1

$(a-b) (a-b) = a^{2} - 2(ab) + b^{2}\\\\(2y-3z) (2y-3z) = 4y^{2} - 2(6zy) + 9z^{2}$

                        = $4y^{2} - 12zy + 9z^{2}$

Answer 2

Answer:

$(2y - 3z) {}^{2}$

=

$(2y) ^{2} - 2(2y)(3z) + (3z) ^{2}$

=

$4y ^{2} - 4y + 6z + 9z$

=

$y ^{2} + 15z$