90 Divided by What Equals 81?
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 90 by to equal 81?
Solving 90 Divided by What Equals 81
Here’s how you would set up this question as an equation:
90
x
=
81
\frac{90}{x} = 81
x 90 = 81
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 90:
90
=
81
∗
x
90 = 81*x
90 = 81 ∗ x
Then we can isolate x on the right side of the equation by dividing both sides by 81:
90
81
=
x
\frac{90}{81} = x
81 90 = 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
=
1.111
x = 1.111
x = 1.111
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 75 equals 81?
46 divided by what equals 9?
What is 10/15 divided by 82?
What is 6/18 divided by 5/3?
What is 26 divided by 14/12?