Math Word Problems?

Question

Mark is 10 years younger than Larry. Larry's age in 8 years will exceed twice Mark's age 3 years ago by 4 years. Hold old are each now.

I have:
L+10=M
L+8=2M-3
what do I do with the 4?

Answer 1

Hi! Well, firstly, your first equation is incorrect:
Mark is 10 years younger than Larry gives L=M+10
The next sentence gives L+8=2(M-3)+4
Substitute the first equation into the second to get:
M+18=2M-2
Which then gives M=20, and so L=30
Hope that helps!

Answer 2

Let Mark's present age be M.
Larry is 10 years older, thus Larry's present age will be (M+10).
In 8 years' time, Larry's age will be (M+10+8 = M+18) years old.
3 years ago, Mark's age (M-3).
Get all into an equation (i.e. Larry's age in 8 years will exceed twice Mark's age 3 years ago by 4 years):
M+18 = 2(M-3) + 4
Carry on to solve for Mark's present age. Then you can find out Larry's present age.

Solution:
M + 18 = 2M - 6 + 4
M = 2M - 2 - 18
20 = M
Hence now Mark is 20 years old and Larry is (20+10 = 30) years old.

Answer 3

M = Mark's current age
L = Larry's current age


If mark is ten years younger than Larry that means you need to add 10 to Mark's age to equal Larry's:

Ten years plus mark's age = larry's age:

M+10 = L

In 8 years, Larry's age will be

L+8

Mark's age three years ago is

M-3

The formula for the second sentence in you problem becomes:

L+8 = 2*(M-3) +4


So solve these two simultaneous equations:

M+10 = L
L+8 = 2*(M-3) +4

M=20, L=30

Answer 4

The second equation should be L + 8 = 2(M - 3) + 4. You take Mark's age three years ago and double it--meaning the -3 is also multiplied by two. Then you add four because it says that Larry's age in 8 years will exceed this value by four.

Answer 5

L=30
M=20

Answer 6

L+10=M -> I think it should be M= L-10