How to write a equation that passes through the points (-1,12) and (4,-8)

y - 12 = (-4/5)(x + 1)

Step-by-step explanation:

Let's use the point-slope formula y - k = m(x - h), where (h, k) is a point on the line and m is the slope of the line.

1.  Find the slope.  As we go from (-1, 12) to (4, 8), x (the run) increases by 5 and y (the rise) decreases by 4.  Thus, the slope is m = rise/run = -4/5.

2.  Plug into the formula (given above) the following:

-4/5 for m, -1 for x and 12 for y:

y - 12 = (-4/5)(x + 1)

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