Question

What number needs to be subtracted from both sides of the equation 40 = 25 + x in order to isolate the variable and solve for x?

Answer 1

x = 15

Explanation:

As given, the equation 40 = 25 + x

As on the R.H.S of the equation, there is one constant and a variable x

As to isolate the variable we have to subtract the same constant so that that constant gives 0.

As we have the constant value 25

So, subtract 25 from both side of the equation, we get

40 - 25 = 25 + x - 25

⇒15 = x

∴ we get

x = 15