Answer :

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]