Answer:
The sum of their ages in 5 years will be 97 years
Step-by-step explanation:
The correct question is
Twelve years ago, Lester was twice as old as Hester. Lester is 21 years older than Hester. What will the sum of their ages be in 5 years?
Let
x ----> Lester's age
y ----> Hester's age
we know that
Twelve years ago, Lester was twice as old as Hester
so
[tex]x-12=2(y-12)[/tex]
[tex]x-12=2y-24[/tex]
[tex]x-2y=-12[/tex] ----> equation A
Lester is 21 years older than Hester
so
[tex]x=y+21[/tex] ----> equation B
substitute equation B in equation A
[tex]y+21-2y=-12[/tex]
solve for y
[tex]-y=-12-21\\-y=-33\\y=33[/tex]
Find the value of x
[tex]x=33+21=54[/tex]
therefore
Lester's age is 54 years and Hester's age is 33 years
The sum of their ages in 5 years will be
[tex](54+5)+(33+5)=97\ years[/tex]