Rebeca had 9/10 of a yardof ribbon. then she gave 7/20 of a yard of friend. how much does she have left?

She has 11/20 yds left

Step-by-step explanation:

We take what she had and subtract what she gave away

9/10 - 7/20

We need to get a common denominator of 20

9/10 *2/2 - 7/20

18/20 - 7/20

11/20

She has 11/20 yds left

step-by-step explanation:

this can be solved first with pythagorean theorem, which tells us to square both legs of the triangle and sum it. this will be equal to the square of the hypotenuse.

the hypotenuse is the side "opposite" the 90 degree angle, which is x.

so we can write using pythagorean theorem,

simplifying:

to further simplify this radical, we need to use the property  

thus