You can put this solution on YOUR website! Let a = Anne's present age
Let b = Bill's present age
:
Write an equation for each statement:
:
"Anne's age is seven-tenths of Bills age."
a = b
or
a = .7b
:
" In 4 years Anne's age will be eight-elevenths of Bill's age."
a + 4 = (b+4)
:
Multiply both sides by 11
11(a+4) = 8(b+4)
:
11a + 44 = 8b + 32
:
11a = 8b + 32 - 44
:
11a = 8b - 12
Substitute .7b for a
11(.7b) = 8b - 12
:
7.7b = 8b - 12
:
+12 = 8b - 7.7b
:
12 = .3b
b =
b = 40 yrs old is Bill's present age
;
;
Check solution:
a = .7(40)
a = 28 yrs now
Check solution in statement:
In 4 years Anne's age will be eight-elevenths of Bill's age."
28 + 4 = (40+4)
32 = (44)
