75 Divided by What Equals 21?
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 75 by to equal 21?
Solving 75 Divided by What Equals 21
Here’s how you would set up this question as an equation:
75
x
=
21
\frac{75}{x} = 21
x 75 = 21
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 75:
75
=
21
∗
x
75 = 21*x
75 = 21 ∗ x
Then we can isolate x on the right side of the equation by dividing both sides by 21:
75
21
=
x
\frac{75}{21} = x
21 75 = 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
=
3.571
x = 3.571
x = 3.571
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 25 equals 76?
1 divided by what equals 83?
What is 4/5 divided by 32?
What is 14/17 divided by 20/10?
What is 77 divided by 2/9?