Algebra 1 · Reasoning with Equations & Inequalities

Solve quadratics using square roots

Solve quadratics using square roots.

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What you’ll learn

Solve quadratics using square roots.

Key idea

A positive squared value has two real signed branches; retain both before undoing the shift.

Retain positive and negative square-root branches before undoing the shift; a valid single branch is not the complete solution set.

Worked example

Enter the exact value or ordered values in the format requested below.

Solve (x+4)²=9; enter both numerical roots separated by a comma.

  1. Both square-root branches are x+4=+3 or x+4=-3.
  2. Undo the shift in both branches: roots -7, -1; substituting either yields square 9.

Answer: -7, -1

Quick Check

Evaluate a worked attempt at solve quadratics using square roots, identify the first invalid step, and provide the correction.

Solve (x+1)²=49: Step 1 keeps only x+1=+7. Step 2 reports x=6. Locate the first invalid step and correct the full root set.

Choose one answer

Show a hint

Read the whole squared expression and its shift.