Question

Solve n3 + 2n2 - 15n = 0 by factoring. Show the factored form of the equation, and the resulting solutions.

Answer 1

Answer:

n = 0, -5 or 3

Step-by-step explanation:

Factorise n:

n³ + 2n² - 15n = 0

n(n² + 2n - 15) = 0

n(n + 5)(n - 3) = 0

Solve n:

n = 0 or (n + 5) = 0 or (n - 3) = 0

n = 0 or n = -5 or n = 3

Answer: n = 0, -5 or 3

Answer 2

given equation is , n³ + 2n² - 15n = 0

or, n(n² + 2n - 15) = 0

or, n(n² + 5n - 3n - 15) = 0

or, n{n(n + 5) - 3(n + 5)} = 0

or, n{(n + 5)(n - 3) } = 0

or, n(n + 5)(n - 3) = 0

hence, n = 0, n + 5 = 0 and n - 3 = 0

n = 0, - 5 and 3

therefore, -5, 0 and 3 are solution of given equation.