### Concept (1)

We can find unknown quantities when we know similar ratios for comparison, using proportions. We find proportions often in word problems, for example those involving baking ingredients, and in comparing similar figures in Geometry. We can represent an unknown quantity in a proportion with a variable, and then solve it using one-step, two-step, or multi-step equation methods.

### Sample Problems (8)

Need help with "Proportions" problems? Watch expert teachers solve similar problems to develop your skills.

Solve:

 -5 = t 2 -8
###### Problem 1
How to solve proportions when x is in the numerator.

Solve:

 m + 3 = 12 5 4
###### Problem 2
How to solve proportions when one numerator is an expression with x.

The ratio of the sale price of a shirt to the original price is 2:3. If the original price is \$18, what's the sale price?

###### Problem 3
How to solve word problems involving proportions.
###### Problem 4
Technique for turning percent problems into proportions that can be solved with cross multiplication
###### Problem 5
Shortcuts for using "mental math" to solve proportional relationships
###### Problem 6
How to solve proportions using cross multiplication
###### Problem 7
Turning ratio notation with a colon into a fractional representation of a proportional word problem
###### Problem 8
Geometry similar triangles problems that are solved using proportions