Question

x^2+10x+?=(?)^2

Answer 1

+25

Answer 2

?=25
?^2=5

Answer 3

we need (a+b)^2=a^2+2ab+b^2

x^2+10x+?=(?)^2
let the number be b
x^2+10x+b^2=(x+b)^2
here a=1x, b=?, 2ab=10x
2ab=10x
\[2*1x*b=10x\]
\[b=\frac{10x}{2x}\]
b=5