First let establish the eqautionlet y be the total costx is the number of orders
y = 3x + 115
since the minimum order is 25x >= 25
then The school can spend a maximum of $800
800 <= 3x + 115
800 - 115 <= 3x685 <= 3x685/3 <= x228.33 <= x
ANSWER
The correct answer is option B
EXPLANATION
The equations are

and

When we multiply the second equation by
, we obtain;

When we combine this new equation with equation (1).

We can see that
has been eliminated from the equation.
We can then, solve for
and then substitute the result in to any of the equations to find
.
Hence the correct answer is option B
If the angle is a perfect 90 degrees then it’s a right angle
U can simplify each number to the bottom. Then determine which number pair u can take out. Put those outside of the square too sign. Numbers with out a pair must stay inside the square room