Question

if the zeroes of the quadratic polynomial are 2 and -3 then a = ?
${x }^{2} + (a + 1)x + b \:$
​

Answer 1

At x= +2;

(2)²+(a+1)(2)+b = 0 >> (1)

At x= -3;

(-3)²+(a+1)(-3)+b = 0 >> (2)

Subtracting (1) & (2) we get,

(2)²-(-3)² + (a+1)(2)-(a+1)(-3) = 0

4-9+2a+2+3a+3 = 0

-5+5a+5 = 0

5a = 0

a = 0