The sum of a number and 7 is the same as double the number increased by 3

So, let’s represent the number as n:

n+7=2n+3

Subtract both sides by 3:

n+4=2n

Now by n:

2n=4

Divide:

n=2

The number is 2

The statement above is the same as the mathematical expression below ...

x + 7 = 2x + 3

We want to solve for x in these types of problems. To do so, we must get all of the "x"s on one side of the equal sign and the constants on the other.

7 - 3 = 2x - x

4 = x

Our answer is x = 4.