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Taking a Square Root to Solve an Equation Taking a Square Root to Solve an Equation Solve: What are the number(s) whose square is 9? Find the x that makes x-7 equal POSITIVE 3 x 7 9 x7 9 x 7 3 2 In order to solve for x, you have to UNDO the squared first (i.e. square root) The square of 3 AND -3 is 9 x 7 3 x 7 3 x 10 x4 Find the x that makes x-7 equal NEGATIVE 3 NOTE: In general, this method only works when there is ONE variable in the equation. Taking a Square Root to Solve an Equation x 3 12 x 3 12 x 3 2 3 Solve: What are the number(s) whose square is 12? 2 Simplify any square roots In order to solve for x, you have to UNDO the squared first (i.e. square root) Do not forget the square of a positive and negative number is positive x 3 2 3 x 3 2 3 Find the x that makes x-3 equal a POSITIVE x 3 2 3 x 3 2 3 EXACT answers Find the x that makes x-3 equal a NEGATIVE x 3 2 3 x 0.464 or 6.464 Is also an acceptable EXACT answer Are acceptable APPROXIMATE answers Taking a Square Root to Solve an Equation Solve: What are the number(s) whose square is -11? x 2 11 x 2 11 2 In order to solve for x, you have to UNDO the squared first (i.e. square root) NOT POSSIBLE The square of a number can not be negative. This equation has NO SOLUTIONS. Taking a Square Root to Solve an Equation Solve: What are the number(s) whose square is 0? Since +0 and -0 are the same number. There is only ONE Answer. 5 10 x 0 5 10x 0 5 10 x 0 2 5 10 x 0 10 x 5 x 12 In order to solve for x, you have to UNDO the squared first (i.e. square root) The square of 0 AND -0 is 0