A train goes at a constant speed. If it covers 150 miles in 2 12 hours, d
How long would it take for that train to cover 100 miles?

x = 1 2/3 hours

Step-by-step explanation:

We can use ratios to solve

150 miles          100 miles

=

2.5 hours          x hours

Using cross products

150x = 2.5*100

divide each side by 150

150x/150 = 250/150

x = 1 2/3 hours

coins of silver or gold

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