Question

Use suitable identity to solve $\left(3a-\frac{1}{2}\right)\left(3a-\frac{1}{2}\right)$

Answer 1

$(3a-\frac{1}{2})(3a-\frac{1}{2})=(3a-\frac{1}{2}{)}^2$

using identity $(a-b{)}^2=a^2-2ab+b^2$

$(3a-\frac{1}{2}{)}^2=(3a{)}^2-2\times 3a\times \frac{1}{2}+(\frac{1}{2}{)}^2$

$(3a-\frac{1}{2}{)}^2=9a^2-3a+\frac{1}{4}$