GIVEN: x2+ax+b ....(1) x2+bx+a ....(2) CALCULATIONS: From equation (1) , the equation is divided by x + 3 that means to solve this equation we have to put x = – 3 in the equation and the remainder is – 1 is taking the right side of the equation then, x2+ax+b ....(1) ⇒9−3a+b=−1(∵x=−3) −3a+b=−10.....(3) Similarly for equation (2) , x=3 x2+bx+a ....(2) ⇒9+3b+a=39 ⇒a+3b=30....(4)
To find value of a and b solving equation (3) and (4) , by multiplying equation (4) with 3, According to figure 10b=80→b=8 put b = 8 in equation (4) , a+3b=30 ⇒a+(3×8)=30 ⇒a=6 ⇒a+b=6+8=14 ∴a+b=14 .