0.19 for one cookie and 0.59 for one doughnut
x for how much one cookie costs and y for how much one doughnut costs
6x+4y=3.5
12x+5y=5.23
solve by substitution: (elimination would work too)
4y=3.5-6x
y=0.875-1.5x
12x+5(0.875-1.5x)=5.23
12x+4.375x-7.5x=5.23
4.5x=0.855
x=0.19
now use x to solve for y:
6(0.19)+4y=3.5
1.14+4y=3.5
2.36=4y
y=0.59
Check the work: 6(0.19)+4(0.59)=3.5
To find the mode you need to put all the numbers given in order, then count them and decide which number occurs the most.
Given the number you have here, we're going to put them in order, like so,
78, 78, 83, 85, 89, 91, 95, 98 (they were in order already)
Now we see which number occurs the most.
The number would be 78
~Hope this helped!
Don't quote me on this because i am not a master at math but im pretty sure its yes because it is a rising by the same values every time it passed through a point on the graph