Question
Solve the equation. Use factoring or the quadratic formula, whichever is appropriate. Try factoring first. If you have any difficulty factoring, then go right to the quadratic formula. (Enter your answers as a comma-separated list.)
(x+2)^2 + (x-7)(x-2)=16
(x+2)^2 + (x-7)(x-2)=16
Answers
Henry
(x+2)^2 + (x-7)(x-2) = 16
x^2 + 4x + 4 + x^2 - 2x -7x + 14 = 16
2x^2 - 5x + 18 = 16
2x^2 - 5x + 2 = 0
A*C = 2*2 = 4 = (-1)*(-4).
Choose the pair of factors whose sum = B
2x^2 - (x+4x) +2 = 0
(2x^2-x) - (4x-2) = 0
x(2x-1) - 2(2x-1) = 0
(2x-1)(x-2) = 0
2x-1 = 0
2x = 1
X = 1/2
x-2 = 0
X = 2
x^2 + 4x + 4 + x^2 - 2x -7x + 14 = 16
2x^2 - 5x + 18 = 16
2x^2 - 5x + 2 = 0
A*C = 2*2 = 4 = (-1)*(-4).
Choose the pair of factors whose sum = B
2x^2 - (x+4x) +2 = 0
(2x^2-x) - (4x-2) = 0
x(2x-1) - 2(2x-1) = 0
(2x-1)(x-2) = 0
2x-1 = 0
2x = 1
X = 1/2
x-2 = 0
X = 2