Question

Use the quadratic formula to find the roots of the equation. 2x2 - 28x + 98 = 0
A. {-7, 7}
B. {7}
C. {-2, 49}
D. no real number solution

Answer 1

2(x^2 - 14x +49) = 0
2(x^2 - 7x - 7x + 49) = 0
2(x(x-7)-7(x-7)) = 0

2(x-7)(x-7) =0

2(x-7)^2 = 0

(x-7)^2 = 0

x-7 = 0

x = 7