Need help solving this math problem. C + 42 = H +M?

Apparently H = M + 20 but I cannot figure out how to solve this one.

Need help solving this math problem. C + 42 = H +M?
Replace H with (M+20)


C + 42 = (M+20) + M


Combine the M's on the right side


C + 42 = 2M + 20


Subtract 20 from both sides.


C + 22 = 2M


This is about all that we can do. Are you supposed to solve for a certain variable?
Reply:I think Jackie missed the C + part. A good rule of thumb is that you need at least the same number of equations as unknowns. In this case C, H, and M are all unknowns and you only have 2 equations if you include H = M + 20.
Reply:with the information that you gave there is only one thing that you can do, substitute H for M+20 in the right side of the equation so that you get


C+42=M+20+M


and if you subtract 42 from both sides and add up the M's you get


C=2M-22 or C=2(M-11)





but you can't go any farther
Reply:what are you supposed to be solving for??
Reply:Unfortunately, as has been said before, there is not enough information to solve this fully. If there are three variables, there must be three separate equation. With one variable just one equation. Two variables two equations etc...


Unfortunately this has three variables and only two equations.
Reply:C + 42 = H + M ... (1)





Since H = M + 20; we can substitute the value of H in the above equation (1)





Hence equation (1) can be rewritten as





C + 42 = M + 20 + M





C + 42 = 2M + 20





2M - 22 - C = 0 ..... (final answer)
Reply:then just plug it in, its easy





H = M + 20


so





C + 42 = M +20 + M





C = 2M +20 - 42





C = 2M - 22





then just pretend that M is x and C is y as in Y = mx + b


and there you go





oh yeah after you find both of them, find out what H =.
Reply:42 = H +M


42 - M = H (moved M across equals sign)





so


H = 42 - M and H = M + 20





so


42 - M = M + 20


42 = 2M + 20


2M = 22


M = 11