Question

The age of Noelle’s dad is 6 less than 3 times Noelle’s age. The sum of their ages is 74. Find their ages

Answer 1

Noelle: 20 Dad: 54

Explanation:

The age of Noelle's Dad is 6 less than 3 times Noelle's age looks like this:

d=3n-6

While the sum of their two ages is 74, looks like this:

n+d=74

The system is:

{d=3n−6

{n+d=74

Now, substitute the first equation into the second equation and solve for n.

n+(3n−6)=74

4n-6=74

Add 6 to both sides

4n=80

Divide both sides by 4

n=20 (<---- Noelle's Age!)

Now plug n into the second equation

d=3(20)-6

d=60-6

d=54 (<---- Noelle's Dad's Age!)

Answer 2

Noelle is 20. Noelle’s dad is 54.