Which pair of fractions has a common denominator that is less than the product of two denominators? a) 2/3 and 3/8 b) 5/6 and 7/11 c) 7/9 and 11/12 or d) 7/10 and 5/7

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