-13/16; -7/8; -15/2; 7/4 hope i helped good luck on ur exam :)
The line of symmetry.
It divides the parabola into to halves that are exactly the same.
Firstly, you do 90 - 42 to get the amount of brownies sold, which is 48. Then, you put 42 and 48 into a ratio like 42:48. After that, all you need to do is simplify to get 7:8.
When solving by substation the answer would be: X= 1 , y= 5