Solving Formulas Solving Formulas z A formula is

Solving Formulas

Solving Formulas z. A formula is an algebraic sentence with more than one variable. z. Since a formula has more than one variable, we must be told which variable to solve for (isolate).

Solving Formulas z. When we isolate one variable in a formula, we need to move other variables and numbers to the other side of the equation. y. To move a variable that is added to the expression, add the opposite variable to both sides. y. To move a variable that is multiplied or divided by the expression, multiply the reciprocal on both sides.

Examples To isolate b , we must move the variable a. Variable a is multiplied by variable b , so multiply both sides by the reciprocal of a. Or divide both sides by a. (Same result) Multiply both sides by . Or divide both side by a. Variable b is now isolated.

Examples To isolate y , we must move the term 3 x away from y to the other side of the equation. The term 3 x is added to variable y , so add -3 x to both sides. ( Or just subtract 3 x. Remember that adding a negative is the same as subtracting. ) Subtract 3 x to both sides. Warning: 9 and -3 x are NOT like terms! Variable y is now isolated.

Examples To isolate a , we must move the term 4 b and the coefficient, 2, away from a. Solving equations means we still need to reverse the order of operations, so take care of adding/subtracting first. Subtract 4 b to both sides. Divide by 2 on both sides. SO 2 2 Warning: c and -4 b are NOT like terms!

Try These! Solve each formula for the stated variable.