Let
x--------> <span>the speed of the boat in mph
we know that
</span>going upstream the speed is x-7
<span>going downstream the speed is x+7
</span>
let the distance be d
<span>time to go upstream = d/(x-7) </span>
<span>time to go downstream = d/(x+7)
</span>
time going upstream is 3 times going downstream
so
<span>3d/(x+7) = d/(x-7) </span>
<span>divide by d </span>
<span>3/(x+7) = 1/(x-7) </span>
<span>3x-21 = x+7 </span>
<span>2x = 28 </span>
<span>x = 14
</span>
the answer is
<span>the speed of the boat in still water is 14 mph</span>
It is the tropical plants. The text asks about population which is defined as the total number of an object or an entity. In scientific researches, samples are drawn from population to explore either qualitatively or quantitatively a phenomenon. Moreover, biologists study plants as subjects in this study.

Change x to y, and y to x.

solve for y:

Your answer is:

Answer:
sure if im able, with what?
Step-by-step explanation: