If var(x)=25 find var(2x+4).
You asked:
Given \(v a \cdot r\left( x \right) = 25\) evaluate the expression \(v a \cdot r\left( 2 x + 4 \right)\).
MathBot Answer:
\[a v r{\left(2 x + 4 \right)} = \frac{25 r{\left(2 x + 4 \right)}}{r{\left(x \right)}}\]
\[a v r{\left(x \right)} = 25\]Solve for $a$: \[a = \frac{25}{v r{\left(x \right)}}\]Substitute $a$ into the given expression: $$\begin{aligned}a v r{\left(2 x + 4 \right)} &= v r{\left(2 x + 4 \right)} \frac{25}{v r{\left(x \right)}} \\ a v r{\left(2 x + 4 \right)} &= \frac{25 r{\left(2 x + 4 \right)}}{r{\left(x \right)}}\end{aligned}$$