*a*+ 6

*b*, to be precise) so we need to find a way to get from what they gave us to what they ask for. Here's what we're given:

3

*a*+ 4*b*=*b*We're already close. Multiplying everything by 2 will get us closer (remember, use what they want as a GUIDE...that's what we're aiming for!):

2(3

*a*+ 4*b) = 2**b*6

*a*+8*b*= 2*b*Now, just subtract 2b from both sides, and we're there!

**6**

**a****+ 6**

**b****= 0**

**That's choice (A).**

It's important to note that in this particular question, it's

*impossible*to solve for the individual variables*a*and*b*. We'd need two equations to do that, and they only gave us one. Doesn't matter, though, since we aren't looking for the individual variables, and don't need them. If I asked you for a cake, I'd want you to bring me a cake, not the ingredients to make one. Same goes for the SAT:**if they ask for an expression, solve directly for the expression**, don't try to find the ingredients.
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