Question

If $(75{)}^2-(70{)}^2=\left[\right(65{)}^2-\left(60{)}^2\right]\left(x\right)$, what is the value of $x$ ?

• A. $\frac{25}{21}$
• B. $\frac{35}{31}$
• C. $\frac{15}{21}$
• D. $\frac{29}{25}$

Answer 1

The correct option is D $\frac{29}{25}$

$(75{)}^2-(70{)}^2=(65{)}^2-(60{)}^2\times \left(x\right)$

$\Rightarrow (75+70)(75-70)=(65+60)(65-60)\times \left(x\right)$

$\Rightarrow x=\frac{145}{135}\Rightarrow x=\frac{29}{25}$