Question 613077
s = S's age
j = J's age
:
Write an equation for each statement:
;
Sarah is one year older than four times Jill's age.
s = 4j + 1
:
The sum of their ages is 13 1/2.
s + j = 13{{{1/2}}}
Replace s with (4j+1)
4j + 1 + j = 13{{{1/2}}}
4j + j = 13{{{1/2}}} - 1
5j = 12{{{1/2}}}
Let use decimals here
5j = 12.5
Multiply both sides by {{{1/5}}}} which is .2
.2(5j) = .2 * 12.5
j = 2.5 age is J's age
then
s = 4(2.5) + 1
s = 10 + 1
s = 11 yrs is S's age