Question

If the value of x is 5, then 3x + what = 20

Answer 1

Let's assume the no. as y

X=5

3x+y=20

3×5+y=20

15+y=20

y=20-15

y=5

Answer 2

If x = 5, then 3x + 5 = 20.

Given: x = 5

To find: 3x + __ = 20.

Solution:

Let us assume the unknown number as y.

   ∴ 3x + y = 20

And we have,

          x = 5

Substituting the value of x on the given equation we get,

        3 × 5 + y = 20

⇒ 15 + y = 20

Shifting 15 to RHS,

        y = 20 - 15

      ∴  y = 5