Question

Marta's jump rope is 10" shorter than four times the length of Dilbert's rope. If both their ropes laid together end to end and measured 120" long, how long is Marta's rope?

Answer 1

Marta's rope is 94"

Explanation:

D = dilberts rope length

M = marta's rope length

Marta's jump rope is 10" shorter than four times the length of Dilbert's rope

M = 4D-10

both their ropes laid together end to end and measured 120" long

M+D = 120

Substitute 4D-10 for M in the second equation

4D-10 + D = 120

Combine like terms

5D-10=120

Add 10 to each side

5D-10+10 =120+10

5D =130

Divide by 5

5D/5 = 130/5

D =26

Now we need to find M

M+D = 120

M +26 = 120

Subtract 26 from each side

M = 120-26

M = 94