Question

The coefficient of x in the equation x²+ px+q =0 was taken as 17 in place of 13, its roots were found to be –2 and –15, The roots of the original equation are –

• A. 3, 10
• B. –3, –10
• C. – 5, –18
• D. None of these

Answer 1

Answer: (B)

–3, –10

Answer 2

x² + px + q = 0. If p = 17 (taken wrong) then roots are –2 and –15

which means product is right but sum is wrong product

= (– 2) × (–15) = $\frac{q}{1}$ Ž q = 30

\ Exact equation Ž x² + 13x + 30 = 0

(x + 3) (x + 10) = 0 Ž x = – 3, –10 are exact roots