Idont understand how to solve this " simple" ..

420 students, 15 days after opening --make sure to check my work with calculators to be 100% sure mk :))

Step-by-step explanation:

When will they be equal:

28x + 4 = -x² + 39x + 64

-x² + 11x + 60 = 0

x = -4 or 15.

Let's now solve for the actual attendance! You can use either equation to plug in 15 because in this case, the attendances are always going to be equal. Let's use the easier equation, though

146%

step-by-step explanation:

c-   36

taxicab circle radius 9 has 4(9) = 36 points