Question

HURRYYYYYYYYYYYYYYYYY! Justin’s doctor said that the expression StartFraction x + y + 5 over 2 EndFraction, where x and y are his parents’ current heights in inches, gives an estimate of how tall Justin will be as an adult. Justin’s work evaluating the formula is shown below. Mom’s height = 54 inches Dad’s height = 71 inches StartFraction 71 + 54 + 5 over 2 EndFraction = 71 + 27 + 5 = 103 inches What error did Justin make? A. He should have made x equal 54 and y equal 71. B. He should have added the values in the numerator before dividing by 2. C. He should have divided the 71 by 2 instead of the 27. D. He should have made the numerator 76 + 59.

Answer 1

B

Explanation:

I did the quiz on edge

Answer 2

Given:

The expression is which gives an estimate of how tall Justin will be as an adult is

`(x+y+5)/(2)`

where, x and y are his parents’ current heights in inches.

Mom’s height = 54 inches Dad’s height = 71 inches.

His calculation:

`(71+54+5)/(2)=71+27+5=103\ inches`

To find:

Justin's mistake.

Solution:

Let x be Dad’s height and y be Mom’s height. So, correct estimation for his height is

`(71+54+5)/(2)=(130)/(2)`

`(71+54+5)/(2)=65`

He should have added the values in the numerator before dividing by 2.

Therefore, the correct option is B.