An important and exam oriented question from polynomials in which we have given a equation 2x²+2ax+5x+10 and x+a is one of its factor and we have been asked to find the value of a.
Kindly give me a detailed solution of this question
RS Aggarwal, Class 10, chapter 2A, question no 20
Given f(x)=2x2+2ax+5x+10
g(x)=x+a
x+a=0
x=−a
f(−a)=2(−a)²+2a(−a)+5(−a)+10
⇒+2a²−2a²−5a+10=0
⇒5a=10
⇒a=10/5
∴a=2