<p>took a real ACT math section from a test administered last year and i got all math right but 1 question which i can't figure out.</p>
<p>For what value of a would the following system of equations have infinitely many solutions?
3x - 2y = 6
6x - 4y = 3a</p>
<p>the correct answer is 4. can anyone tell how to get that?</p>
<p>For the system to have an infinite amount of solutions, the two equations would have to be identical. So basically all you do is make them identical by multiplying the first equation by 2. If you do this, you get 6x-4y=12. Since the second equation is 6x-4y=3a, then 3a must equal 12 for the equations to be identical. If 3a=12, then a=4.</p>
<p>wow i am so stupid i should have had a 36, but i put 12 as an answer because i forgot to divide by 3.</p>