Question

What is the value of c such that x^2-20x+c is a perfect-square trinomial?

Answer 1

c=100

Explanation:

To complete the square, it would really help if the coefficient of x^2 is 1 which is so formula for c in this case is just (b/2)^2

So (-20/2)^2

simplifying gives

(-10)^2

100

c=100

Answer 2

100

Explanation:

The question is on making the equation a perfect square

Given ;

`x^2 - 20x + c`

To get c;

`c=((b)/(2) )^2`

where ;

`b= -20`

`c= ((-20)/(2) )^2 = 10^2 = 100`