Question 1132934: Mr.Santos is 25years older than his son, 8 years ago, he was 7 more than 10 times as old as his son.What are their present ages?
Found 3 solutions by ankor@dixie-net.com, addingup, greenestamps:
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! let m = Mr Santos present age
let s = son's
:
write an equation for each statement
:
Mr.Santos is 25years older than his son,
m = s + 25
8 years ago, he was 7 more than 10 times as old as his son.
m - 8 = 10(s - 8) + 7
m - 8 = 10s - 80 + 7
m = 10s - 73 + 8
m = 10s - 65
From the 1st equation, replace m with (s+25)
s + 25 = 10s - 65
25 + 65 = 10s - s
90 = 9s
s = 90/9
s = 10 yrs old is the son's present age
then
m = 10 + 25
m = 35 yrs is Mr Santos age now
:
;
Check this in the statement
"8 years ago, he was 7 more than 10 times as old as his son."
35 - 8 = 10(10 - 8) + 7
27 = 10(2) + 7
Answer by addingup(3677)  (Show Source):
You can put this solution on YOUR website! Santos: x
son: y
~~~~~~~~~~~~~~~~~~~~
x = y + 25
x - 8 = 10(y-8) + 7
y + 25 - 8 = 10y - 80 + 7
y + 17 = 10y - 73
-9y = -90
y = 10 The son is 10 years old
x = y + 25 = 10 + 25 = 35 The father is 35 years old
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Check:
8 years ago, father was 7 more than 10 times as old as his son:
35 - 8 = 27
10(10 - 8) + 7 = 27
10(2)+ 7 = 27
20 + 7 = 27 Correct
Answer by greenestamps(13200)  (Show Source):
You can put this solution on YOUR website!
The difference in their ages will always be 25 years.
8 years ago, Mr. Santos was 7 more than 10 times as old as his son. If x was his son's age then, his age then was 10x+7; then the difference in their ages was (10x+7)-x = 9x+7.
So find when 9x+7 is equal to 25:
Solve for x; that will be the son's age 8 years ago.
Then add 8 to get the son's current age; then add 25 to get Mr Santos's current age.
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