Now consider just the second sentence of the multistep word problem. sentence 2: if four times the brother's age is subtracted from three times the sister's age, the difference is 40. give an equation that represents this statement using b as the age of the brother and s as the age of the sister. express your answer in terms of s and b.

4b - 3s = 40

4b = 40 + 3s

b = 40 - 3s/4

4b - 3s = 40

4b - 40 =3s

4b - 40 /3 = s

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