Back to Rearrange formulas — Problem 4 · Task Set 30

Exercises: Rearrange Formulas to Highlight a Quantity of Interest

Show each algebraic step clearly. State which operation you apply to both sides at each step.

Grade 9·20 problems·~30 min·Common Core Math - HS Algebra·standard·hsa-ced-a-4

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Fluency Practice

Rearrange each formula to solve for the indicated variable. Show your steps.

$Contrast card showing the common error of forgetting the square root step (wrong) versus correctly taking the square root of both sides when isolating a squared variable (correct).$

Area of a circle: $A = \pi r^2$ . Rearrange to solve for $r$ (take the positive root). Then find $r$ when $A = 100\pi$ cm². Give your answer in centimetres.