15 Divided by What Equals 40?
Methods
Setting up the problem:
In a problem like this, the “what” means that we’re working with a variable. The most common variable used in math is “x”. So we could say what number, x can we divide 15 by to equal 40?
Solving 15 Divided by What Equals 40
Here’s how you would set up this question as an equation:
15
x
=
40
\frac{15}{x} = 40
x 15 = 40
The goal of the problem is to solve for x. To do this we need to change the equation so that x is alone on one side of the equation.In this case, it can be done in two steps. The first step is to multiply both sides by x to isolate 15:
15
=
40
∗
x
15 = 40*x
15 = 40 ∗ x
Then we can isolate x on the right side of the equation by dividing both sides by 40:
15
40
=
x
\frac{15}{40} = x
40 15 = x
When we simplify the new equation, we can solve for x. In this example, we will round to the nearest three decimal places if that’s needed.
x
=
0.375
x = 0.375
x = 0.375
Practice Other Division Problems Like This One
If this problem was a little difficult or you want to practice your skills on another one, give it a go on any one of these too!
What divided by 82 equals 54?
30 divided by what equals 8?
What is 2/7 divided by 85?
What is 12/18 divided by 16/5?
What is 68 divided by 20/14?