Question

If $49a^2-b=(7a+\frac{1}{2})(7a-\frac{1}{2}),$then find the value of b.

Answer 1

$49a^2-b=(7a+\frac{1}{2})(7a-\frac{1}{2})$

$\Rightarrow 49a^2-b=49a^2-{\left(\frac{1}{2}\right)}^2$

$\Rightarrow -b=\frac{-1}{4}$

So $b=\frac{1}{4}$.