Question

find a and b if a+b=4 and x+2 is factor of polynomial x^2+ax+2b​

Answer 1

Answer:

a = 3, b = 1.

Step-by-step explanation:

Since, (x +2) is a factor of the given polynomial,

therefore, if we put x = -2, then the value of the polynomial will be zero.

=> (-2)^2 + a(-2) + 2b = 0

=> 4 - 2a + 2b = 0

=> 4 = 2a - 2b

=> a - b = 2...(ii) and a + b = 4 ...(i) {given}

Adding these two equations, we get,

2a = 6 => a = 3

for a = 3, b = 1

Hence, a = 3, b = 1.