
Nathan B. answered 09/25/18
Tutor
5
(20)
Elementary and Algebraic skilled
Here's what we know:
L + 8 = 4(s + 8) (Mr. Lee will be 4 times his son's age in 8 year's time)
L + 8 + s + 8 = 50 (Their ages added together will also equal 50)
L + s + 16 = 50 (the same equation as above, only simplified)
To solve this, we need to isolate a variable in the 2nd equation. Let's isolate L:
L + s + 16 = 50
Subtract 16:
L + s = 34
subtract s:
L = 34 - s
Now that we have a value for L, we can plug it into the first equation:
34 - s + 8 = 4(s + 8)
Simplify:
42 - s = 4(s + 8)
Distribute:
42 - s = 4s + 32
Subtract 32 from both sides:
42 - s - 32 = 4s + 32 - 32
10 - s = 4s
add s:
10 - s + s = 4s + s
10 = 5s
Divide by 5:
10/5 = 5s/5
2 = s
Insert this into the original equations to find Mr. Lee's age and check your answer.