Question

if a and b are roots of x2 -7x +12

find 3a +4b​

Answer 1

Answer:

by middle term spitting

x2-7x+12

x2-6x-2x+12

X(x-6)-2(x-6)

(x-2)(x-6)

therefore,

a=x-2

b=x-6

so,

3(x-2)+4(x-6)

=3x-6+4x-24

=ANS.7x-30

HOPE IT HELPS.