Question

Find the roots of the following quadratic equations by factorisation: 14x+5-3x2

Answer 1

Answer:

p(x)=–3x²+14x+5

Let, p(x)=0 (as, x is a zero)

so, p(x)=–3x²+14x+5=0

or 3x²–14x–5=0

Here, sum of zeroes=–14

product of zeroes=–15

so, p(x)=3x²–15x+x–5=0

3x(x–5)+1(x–5)=0

(3x+1)(x–5)=0

either, 3x+1=0 or x–5=0

so, x=–1/3 or x=5

Answer 2

Answer:

5 or -1/3

Step-by-step explanation:

    14x + 5 - 3x² = 0

⇒ -3x² + 14x + 5 = 0

⇒ 3x² - 14x - 5 = 0

⇒ 3x² - (15 - 1)x - 5 = 0                                            (15 and -1 as the factors of -15)

⇒ 3x² - 15x + x - 5 = 0

⇒ 3x(x - 5) + 1(x - 5) = 0

⇒ (x - 5)(3x + 1) = 0

⇒ either (x - 5) = 0                                                      or (3x + 1) = 0

           ⇒ x = 5                                                            ⇒ x = -1/3