What number must you add to complete the square x210x37 A 25

What number must you add to complete the square? x^2+10x=37 A. 25 B. 20 C. 5 D. 10

Given x²+10x=37

Here, on the LHS it should be changed into square.For that which number can be added.

For a complete square, (a+b)²=a²+2ab+b²

Compare it with the given equation,

x=a, 10x=2ab, b² is the number to be added to make it square

10x=2ab

10=2b

b=5

So,b²=5²=25

25 is the number to be added.

Therefore, x²+10x+25=37+25

(x+5)²=62

So, Option A is the correct one.