Question

The product of two successive multiple of 5 is 300

Answer 1

Ans : 15, 20 or -15, -20

Hint :

Let the successive multiples of 5 be 5x and

5(x +1)Then,

5x.5(x + 1) = 300

x2+ x = 12

x2+x-12=0

Answer 2

The product of two successive integral multiples of 5 is 300. Determine the multiple

SOLUTION

Given that the product of two successive integral multiples of 5 is 300.

Let the integers be 5x, and 5(x + 1)

Then, by the integers be 5x and 5(x + 1)

Then, by the hypothesis, we have

5x ∙ 5(x + 1) = 300

⇒ 25x (x + 1) = 300

⇒ 2 + = 12

⇒ 2 + - 12 = 0

⇒ 2 + 4 - 3 - 12 = 0

⇒ x(x + 4) -3(x + 4) = 0

⇒ (x + 4) (x – 3) = 0

⇒ x = -4 or x = 3

If x = -4, 5x = -20, 5(x + 1) = -15

x = 3, 5x = 15, 5(x + 1) = 20

∴ The two successive integral multiples are 15, 20 or -15, -20.