Question

Find the value of c that makes x²-4x+c a perfect square.​

Answer 1

Explanation:

Given,

`\sf x^2+4x+c \: \: \: \: \: \: \\ \\ \sf x^2+2(2)x+c \\`

We know that,

`\boxed{ \sf \bull(a+b)^2=a^2+2(a)(b)+b^2} \\`

`\sf x^2+2(2)x+c \: \: \: \\ \sf x^2+2(2)x+2^2 \\ \sf(x+2)^2 \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \\`

Therefore , the value of c is 4