(A) 15
(B) x(x + 5) = 4
Hint:
x (x + 5) = 4
∴ x² + 5x – 4 = 0
Here, x is the only variable and maximum index of the variable is 2.
a = 1, b = 5, c = – 4 are real numbers and a ≠ 0
(A) 7
Hint:
(C) 10
Hint:
Comparing 2x² – 5x + 7 = 0 with ax² + bx + c = 0, we get a = 2 and b = – 5
x² – 15x + 54 = 0
∴ x² – 9x – 6x + 54 = 0
∴ x(x – 9) – 6(x – 9) = 0
∴ (x – 9) (x – 6) = 0
∴ x – 9 = 0 or x – 6 = 0
∴ x = 9 or x = 6
∴ The roots of the given quadratic equation are 9 and 6.
