Question

Find the value of $y$, if :

$3y={\left(25\right)}^2-{\left(13\right)}^2$

Answer 1

Step 1 : We can apply identity of ${\left(a\right)}^2-{\left(b\right)}^2$ on R.H.S

$$\begin{gathered} 3y=(25-13)(25+13) \\ =\left(12\right)\left(38\right) \\ =456 \end{gathered}$$

Step 2 :Find the value of $y$

$$\begin{gathered} y=\frac{456}{3} \\ =152 \end{gathered}$$

Hence the value of $y$ is $152$