If seven integers are selected from the first 12 negative integers, how many pairs of these integers will have a sum of −13?

At least 1, possibly as many as 3.

There are 6 pairs of integers among those from -1 to -12 that will sum to -13. If you choose 7 integers, you may only choose one pair, or you may choose as many as three pairs.

One to three pairs will sum to -13.

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

$649.60

step-by-step explanation: