Respuesta :
a. b+8
b. b+8=21
c. b=21-8=13 Billy is 13 now
d. Ann was ten years old six years ago. How old is she now? a-6=10, a=16. Ann is 16 now.
b. b+8=21
c. b=21-8=13 Billy is 13 now
d. Ann was ten years old six years ago. How old is she now? a-6=10, a=16. Ann is 16 now.
Answer:
"Billy's age in 8 years", this refers to a future age, which implies adding 8 years to the present age. The expression would be:
[tex]B+8[/tex]
"In 8 years Billy will be 21 years", this expression, using the first one too, would be:
[tex]B+8=21[/tex]
How old is Billy now?
The answer to this question is the solution of the second equation:
[tex]B+8=21\\B=21-8=13[/tex]
Billy is 13 years old now.
A problem for the expression [tex]A-6=10[/tex] could be:
Six years ago Adam was 10 years old.
The six years in the past refers subtracting, and the age back then is the result of that difference.