9 c − 4 − c 2 = − 7 9 c - 4 - c 2 = - 7 Move 7 7 to the left side of the equation by adding it to both sides. 9 c − 4 − c 2 + 7 = 0 9 c - 4 - c 2 + 7 = 0
Add − 4 - 4 and 7 7 . 9 c − c 2 + 3 = 0 9 c - c 2 + 3 = 0 Factor − 1 - 1 out of 9 c − c 2 + 3 9 c - c 2 + 3 . Tap for more steps... − ( c 2 − 9 c − 3 ) = 0 - ( c 2 - 9 c - 3 ) = 0 Multiply each term in − ( c 2 − 9 c − 3 ) = 0 - ( c 2 - 9 c - 3 ) = 0 by − 1 - 1 Tap for more steps... c 2 − 9 c − 3 = 0 c 2 - 9 c - 3 = 0 Use the quadratic formula to find the solutions. − b ± √ b 2 − 4 ( a c ) 2 a - b ± b 2 - 4 ( a c ) 2 a Substitute the values a = 1 a = 1 , b = − 9 b = - 9 , and c = − 3 c = - 3 into the quadratic formula and solve for c c . 9 ± √ ( − 9 ) 2 − 4 ⋅ ( 1 ⋅ − 3 ) 2 ⋅ 1 9 ± ( - 9 ) 2 - 4 ⋅ ( 1 ⋅ - 3 ) 2 ⋅ 1 Simplify. Tap for more steps... c = 9 ± √ 93 2 c = 9 ± 93 2 The final answer is the combination of both solutions. c = 9 + √ 93 2 , 9 − √ 93 2 c = 9 + 93 2 , 9 - 93 2 The result can be shown in multiple forms. Exact Form: c = 9 + √ 93 2 , 9 − √ 93 2
