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25. 5. 2. c =. =. 4. 2. EXAMPLE 1. Complete the square. Find the value of c that makes the expression x 2 + 5 x + c a perfect square trinomial. Then write the expression as the square of a binomial. STEP 1.
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25 5 2 c = = 4 2 EXAMPLE 1 Complete the square Find the value of cthat makes the expression x2 + 5x + ca perfect square trinomial. Then write the expression as the square of a binomial. STEP 1 Find the value ofc.For the expression to be a perfect squaretrinomial, c needs to be the square of half thecoefficient ofbx. Find the square of half the coefficient of bx.
5 2 x2 + 5x +c=x2+ 5x + Substitute 25 for c. 4 25 = 4 x 2 + EXAMPLE 1 Complete the square STEP 2 Write the expression as a perfect square trinomial. Then write the expression as the square of a binomial. Square of a binomial
9 3 4 2 ANSWER ANSWER 16; (x + 4)2 36; (x 6)2 ANSWER ; (x )2 for Example 1 GUIDED PRACTICE Find the value of cthat makes the expression a perfect square trinomial. Then write the expression as the square of a binomial. 1. x2 + 8x + c 2. x2 12x + c 3. x2 + 3x + c