Jane is going to fence in her back yard. she has bought 100 feet of fencing and knows that she wants to fence in a rectangular area where one side will be the back of her house. she knows her house if 30 ft across the back. which of the following is the equation that jane can use to figure out how far back from the house she can fence in?
a) 30(x+30) = 100
b) 30x = 100
c) x+x+30 = 100
d) x+30 = 100

answer: howdy

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