1. Is 2/12 = 5/28 a true proportion? Step 1. Cross multiply.

2 x 28 = 12 x 56
56 = 672

Step 2. is the proportion true?

, because the cross products are not .

The proportion true, because 2/12 and 5/28 equivalent ratios.

Cross multiply:

⇒ 2 x 28 = 5 x 12

⇒ 56 = 60

Is this proportion true?

No, because the cross products are not equal.

The proportion is not true, because 2/12 and 5/28 are not equivalent ratios.

c.

step-by-step explanation:

she should of added 9^2 and 12^2. that is because it is a^2+b^2=c^2. c^2 is the hypotenuse and should always be bigger than the other two numbers. which is why she should of added 9 squared and 12 squared together instead of 15 squared.