Multiply the first equation by -1
-3x-y=-4
2x+y=5
Add them up
-x=1
So x=-1
And y=7
So the first option is correct
Answer:


Step-by-step explanation:
Given




Required
The number of each coin
The total coins can be represented as:


So, the worth of the coin is:

The equations to solve are:


Make d the subject in: 

Substitute
in 


Collect like terms


Solve for q


Substitute
in 


So:


The answer would be 30%
Explanation~
Well, you would have to add 27 and 23 first since, it says, “What percentage of the twelfth grade students have more than one college in mind” then, you’d have to figure out the percentage from there. And the percentage would be, 29.4117647059% of 170, round that to the nearest percent and it’s 30 I’m pretty sure.