So we multiply both sides by 7 to make 2/7 a whole number. You get 2(4q+7/2)-21q=63. Then take 4q+7/2 out of parentheses and you get 8q+7-21q=63. Subtract 7 on both sides and add the q’s together, -13q=56. Divide both sides by -13 and you get around 4.3
        
             
        
        
        
Remainder: 6 when divided by 12
So 12x6= 72 
Original number: 72
72/9= 8
The remainder: 8
        
             
        
        
        
21 sets of nachos =£52.50
56 drinks = £28
= 77 in total =£80.50
        
             
        
        
        
Answer: 80 ounces of yellow paint
Working:
As we know 2 ounces of yellow paint to 5 ounces of red paint, we can make a ratio:
2:5
Then we look at the question which says 200 ounces of red paint, so we replace the 5 ounces of red paint in the ratio with 200.
2:200
Then we figure out how much the 5 has been multiplied by to get to 200. We do this by doing
200 divide 5 = 40
Therefore we times the 2 ounces of yellow paint by 40 which gets us:
80:200
We can think of it as a fraction too to confirm our answer:
Simplify 80 / 200
We get 2 / 5.
If you need me to further explain something please just ask :)