### Home > GB8I > Chapter 7 Unit 8 > Lesson INT1: 7.1.5 > Problem7-63

7-63.

Solve for the indicated variable by rewriting each equation.

Read the Math Notes box for section 3.3.1 to review properties for solving equations.

1. $V = LWH$ (for $W$)

The equation contains multiplication. To undo the multiplication divide both sides by $L$ and $H$.

1. $y=\frac { x } { 2 } + 3$ (for $x$)

When solving an equation, use the Addition or Subtraction Property of Equality first to isolate the term with the variable. In this case you will be adding the opposite of $3$. Then use the Multiplicative Property of Equality.

$x = 2(y − 3) = 2y − 6$

1. $\frac { E } { R } = I$ (for $R$)

Use the Multiplicative Property of Equality and multiply both sides of the equation by $R$.

1. $2x + \frac { 1 } { y }=3$ (for $y$)

Add $−2x$ to both sides of the equation.

Multiply both sides of the equation by $y$.

Divide both sides of the equation by $(3 − 2x)$.

$y=\frac{1}{\left(-2x+3\right)}$