Solve the equation x ^ 2-20 = x If the equation has more than one root, write the largest of the roots in your answer

x ^ 2 – 20 = x;
x ^ 2 – x – 20 = 0;
D = b ^ 2 – 4 * a * c = (- 1) ^ 2 – 4 * 1 * (- 20) = 1 + 80 = 81;
x1 = (- (- 1) + 9) / 2 = (1 + 9) / 2 = 10/2 = 5;
x2 = (1 – 9) / 2 = – 8/2 = – 4;
Examination:
For x = 5, then:
5 ^ 2 – 20 = 5;
25 – 20 = 5;
5 = 5;
Right;
For x = – 4, then:
(- 4) ^ 2 – 20 = – 4;
16 – 20 = – 4;
– 4 = – 4;
Right;
Answer: Larger root x = 5.