Question

The value of m in the following equation $x+9=20$ is

• A. 11
• B. 9
• C. 10

Answer 1

The correct option is A 11

Given expression is x + 9 = 20

The values of x are given as 9, 10 and 11.

Putting x = 9 in x + 9 = 20, we get:

LHS = 9 + 9 = 18

RHS = 20

So, LHS ≠ RHS.

∴ Value of x can't be 9.

Now, putting x = 10 in x + 9 = 20, we get:

LHS = 10 + 9 = 19

RHS = 20

So, LHS ≠ RHS.

∴ Value of x can't be 10.

Now, putting x = 11 in x + 9 = 20, we get:

LHS = 9 + 11 = 20

RHS = 20

Here, LHS = RHS.

Hence, x = 11 is the solution of the equation x + 9 = 20.