The answer is B. I used the trigonometric sine formula



And

Complementary angles add up to 90 degrees.
So to find A you would need to add A and B together and equal it to 90 (3x+25+5x-7=90)
Combine like terms together (8x+18=90)
Subtract 18 from night sides (8x=72)
Divide by 8 on both sides (x=9)
Then to find A substitute x into its equation (3(9)+25)=(27+25)=52
A=52 I think
I believe by the first equation they are referring two a representation of the total amount of money made up by the two types of coins. I found this to be 0.05x + 0.10y = 3.50
In my work I solved for the amount of each coin- I assume this is what the final step of your problem entails. If you need any help understanding/ I misinterpreted something please feel free to comment and ask :)
#5c coins or x= 36
#10c coins or y= 17
How many apples are in there
1/5 of a metre. 0.2m. 20cm. However you like to write it :)
This is because 3/5 is being divided by 3. So a third of 3/5 is 1/5, just as a third of 3 is 1.
Also, if you change it decimals, you get 0.6m ÷ 3 = 0.2m. You can then change it to cm if you like. 0.2m, 20cm, 1/5 of a metre. They're all the same thing and equally acceptable as an answer.
Hope I helped :)