how to solve equations with variables on both sides

Question

anonymous · Answer

I just took a test and for some reason, I can't grasp it.

ddcamp · Answer

Isolate the variable to one side:
Examples:
3x + 2 = 2x → (Subtract 2x from both sides) → 3x - 2x + 2 = 0 → x+2 = 0

anonymous · Answer

Ok and I'm stuck on a word problem: 
Dan and Sydney are getting high-speed internet access at the same time. Dan's provider charges $60 for installation and $42.95 per month. Sydney's peovider has free installation and charges $57.95 per month. After how many months will Dan and Sydney have paid the same amount for high-speed Internet service?

anonymous · Answer

Help?

ddcamp · Answer

Let D be the amount that Dan pays, S be the amount that Sydney pays, and m be the number of months:
D = 60 + 42.95×m
S = 57.95×m

We are looking for when they've payed the same amount, or when D=S, or:
60 + 42.95m = 57.95m

anonymous · Answer

So when I solve 60+42.95m=57.95 , I will get my answer?

anonymous · Answer

Please help!

ddcamp · Answer

Subtract 42.95m from both sides:
60 = 57.95m - 42.95m

anonymous · Answer

Don't you subtract the number without the variable first?

anonymous · Answer

I'm lost!