The number is 18.
In order to find this, we need to take each side and turn them into mathematics statements.
Five times the sum of a number and 3.
5(x + 3)
3 times the difference of twice the number and 1
3(2x - 1)
Now that we have these, we can set them equal to each other and solve.
5(x + 3) = 3(2x - 1) ----> Distribute
5x + 15 = 6x - 3 -----> Subtract 5x from both sides
15 = x - 3 -----> Add 3 to both sides
18 = x