x equals 4 and y equals 5 . so the formula would be 5x+12y=80 and if we need 4 of the small boxes we sub x for 4 and we get 5(4) =20. Next, 80 minus 20 is 60, and the equation would now be 12y=60. we now divide both sides by 12 and we get left with y=5. 5x + 12y = 80 5(4) + 12(5)=80 20+60=80. That is all. I hope that doesn't sound confusing
Solutions
3 + 7 > unknown
10 > Answer
The answer to this question can be any number less than 10. Therefore the answer could be either of -8, -3, 0, 1, 2, 3, 9.
Pic isnt loading, what does it say?
As the fellow above said, the particle does make a U-turn at the vertex, and we can find that out by getting the derivative of s(t) and zeroing it out to get the point of the horizontal tangent.
Bearing in mind that ds/dt is really v(t) or the velocity equation, so when we zero out the ds/dt, is the same as saying the velocity went to 0, since it got zeroed out, and then the particle goes over the vertex and changes direction.

the negative acceleration value, simply means a decreasing rate of change, so, it means the particle is slowing down and possibly coming to a stop before changing direction again.