I think it is 20 seconds because when you multiply six times x, you get twelve. And in this case, the x equals two. So, because you multiplied two to six, you do the same thing to the ten seconds, which is twenty. Sorry if this is the wrong answer.
Implicit expression refers to equation that are not strictly expressed in terms of y and x separately. In this case, the derivative of expression
<span>sqrt(xy)=x^2y+1 is
sqrt x * 0.5 y ^-0.5 dy + </span>sqrt y<span> * 0.5 x ^-0.5 dx= x^2 dy + 2xy dx
dy (x^2 - 0.5 (</span>x/y) ^0.5) = dx (2xy - 0.5 (y<span>/x)^0.5)
dy/dx = </span>(2xy - 0.5 (y/x)^0.5) / (x^2 - 0.5 (<span>x/y) ^0.5)</span>
A. This is correct. When you transfer n to the other side, that would be the reciprocal power of a.
b. This is incorrect, because this contradicts with choice a.
c. This is correct. When a number is raised to a "1/n" fraction, that is equivalent to the nth root of the number.
d. This is incorrect, because it is not equivalent to the given equation.
<em>Thus, the answers are A and C.</em>
