Question

the coefficient of x^2 in the expression (a+x)4 is 640. what is the value of a?

Answer 1

Answer:

The value of a in the expression of (a+x)^4 is a=10.327

Step-by-step explanation:

To find the value of a in the expansion of (a+x)^4, first we have to write the general form of binomial expansion. that is,

(a+x)^4 = a^4+4a³x+6a²x²+4ax³+x^4

it is given that the coefficient of x² is 640,

that means 6a²=640 (we can see in the above expansion the term 6a²x² implies the coefficient of x² is 6a²)

therefore, a² = 640÷6

                     = 106.667

implies      a = √106.667

                    = 10.327

thank you