Practice Problems

Answers

Formulas may contain multiple variables, along with known numbers and letters that stand for known constants like ‍$$\pi$$.

We can highlight a certain variable in the formula by treating the formula as an equation where we want to solve for that variable.

  1. In this case, we need to solve the equation $$F=\frac{9}{5}C+32$$ for C.

    $$F=\frac{9}{5}C+32$$

    $$F-32=\frac{9}{5}C$$

    $$\frac{5}{9} \cdot (F-32)$$

    This is the result of rearranging the formula to highlight the measure in degrees Celsius:

    $$C=\frac{5}{9} \cdot (F-32)$$

  2. In this case, we need to solve the equation $$U=\frac{W}{O}$$ for O.

    $$U=\frac{W}{O}$$

    $$U \cdot =W$$

    $$O=\frac{W}{U}$$

    This is the result of rearranging the formula to highlight the hourly output per worker:

    $$O=\frac{W}{U}$$

  3. In this case, we need to solve the equation

    $$A=\frac{1}{2}(b+c)h$$ for h.

    $$A=\frac{1}{2}(b+c)h$$

    $$\frac{2A}{b+c}=h$$

    This is the result of rearranging the formula to highlight the height:

    $$h=\frac{2A}{b+c}$$

  4. In this case, we need to solve the equation $$S = \frac{D}{T}$$ for T.

    $$S = \frac{D}{T}$$

    $$S \cdot T = D$$

    $$T = \frac{D}{S}$$

    This is the result of rearranging the formula to highlight time:

    $$T = \frac{D}{S}$$