Two coworkers picked up some writing instruments at
the office supply store. Ava
selected 9 boxes of pencils
and 4 boxes of ballpoint
pens, paying $30. Next, Tony
spent $39 on 6 boxes of
pencils and 9 boxes of
ballpoint pens. How much
does a box of each cost? using elimination method.

45

step-by-step explanation:

answer: 204

step-by-step explanation:

we are told that the revenue is

x⋅(4080−10x)=−10x^2+4080x

this is a quadratic function, so to maximize it we should find the x-value of its vertex. recall that the x-value of the vertex of the parabola ax^2+bx+c is given by the formula −b/2a.

so in this case, we have a=−10 and b=4080, so the x-value of the vertex is

−b/2a= −(4080)/2(−10)=204

110

step-by-step explanation:

based on the question i am guessing that it is a typo for abc

so the rectangle is 80cm (area)

now to find the area of a triangle.

base times height.

4 times 8.

your answer is 96cm.

hope this .