Question 1170721
m = Mom's present age
c = Chad's
g = Grandpa's
:
Write an equation for each statement, arrange to get c an g in terms of m
:
Chad's mom is ten years younger than three times Chad's age.
 m + 10 = 3c
 3c = m + 10
 c = {{{(m+10)/3}}}
His grandpa is 28 years older than his mom.
 g = m + 28
If Chad's grandpa were three years older, he would be four times Chad's age.
 g + 3 = 4c
Replace c with {{{(m+10)/3}}} and g with (m+28)
(m+28) + 3 = 4({{{(m+10)/3}}})
m + 31 = 4({{{(m+10)/3}}})
Multiply both sides by 3, get rid of the fraction on the right
3(m+31) = 4(m+10)
3m + 93 = 4m + 40
93 - 40 = 4m - 3m
53 = m
Mom's age is 53
Find the age of his grandpa.
g = 53 + 28
g = 81 is grandpa's age
:
:
Check solution in the statement
"If Chad's grandpa were three years older, he would be four times Chad's age."
(Chad is {{{(53+10)/3}}} = 21)
81 + 3 = 4(21)
84 = 84