Proportions

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal.

Front

How do you solve for x in a proportion?

Back

To solve for x in a proportion, cross-multiply and then isolate x.

Front

If a car travels 280 miles in 7 hours, what is its speed in miles per hour?

Back

Speed = Distance/Time = 280 miles / 7 hours = 40 miles per hour.

Front

What is the formula for direct variation?

Back

The formula for direct variation is y = kx, where k is the constant of variation.

Front

If k = 5 in the proportion a/b = k, what is the relationship between a and b?

Back

a = 5b, meaning a is 5 times b.

Front

How do you find the constant of proportionality?

Back

The constant of proportionality can be found by dividing one quantity by the other in a proportional relationship.

Front

What does it mean if two quantities are directly proportional?

Back

If two quantities are directly proportional, as one quantity increases, the other quantity increases at a constant rate.

Front

Solve for w: 3/4 = w/12

Back

w = 9.

Front

What is the cross-multiplication method?

Back

Cross-multiplication is a method used to solve proportions by multiplying the numerator of one ratio by the denominator of the other ratio.

Front

If x/4 = 3/12, what is the value of x?

Back

x = 1.