Question

choose the most appropriate strategy and then use it to solve the quadratic equation.
7. (x-8)^2=121
8. 2a^2=8a-6
9. x^2+12x+36=4
10. x^2-x+30=0

Answer 1

 (x-8) ^ 2 = 121
 (x-8) = + / - root (121)
 x = 8 +/- root (121)
 The solutions are:
 x1 = 8 + root (121)
 x2 = 8 - root (121)
 2a ^ 2 = 8a-6
 2a ^ 2-8a + 6 = 0
 a ^ 2-4a + 3 = 0
 (a-1) (a-3) = 0
 The solutions are:
 a1 = 1
 a2 = 3
 x ^ 2 + 12x + 36 = 4
 x ^ 2 + 12x + 36-4 = 0
 x ^ 2 + 12x + 32 = 0
 (x + 4) (x + 8) = 0
 The solutions are:
 x1 = -8
 x2 = -4
 x ^ 2-x + 30 = 0
 x = (- b +/- root (b ^ 2 - 4 * a * c)) / 2 * a
 x = (- (- 1) +/- root ((- 1) ^ 2 - 4 * (1) * (30))) / 2 * (1)
 x = (1 +/- root (1 - 120))) / 2
 x = (1 +/- root (-119))) / 2
 x = (1 +/- root (119) * i)) / 2
 The solutions are:
 x1 = (1 + root (119) * i)) / 2
 x2 = (1 - root (119) * i)) / 2