These used to really confuse me!
t + h + d = 70
h = t + 6
d = 2t
Since h and d each equal something related to t, we can substitute one side of the equal sign for the other.
t + t + 6 + 2t = 70
Remember that t = 1t, but we don't right it that way. We can't add t and 6 because they are not like terms, but t + t + 2t = 4t.
4t + 6 = 70
We always do the opposite operation to get the variable by itself. Since we have + 6, we subtract 6 from both sides, since adding six and taking away 6 leaves us with 0.
4t = 64
4t means 4 times t, so we divide. 4/4 = 1, but we don't write 1t.
t = 16
I bet you can get the rest!
