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.