<u>Answer:</u>
r = 
<u>Step-by-step explanation:</u>
Multiply both sides by r + 120.
<em>t </em>(<em>r </em>+ 120) = 120<em>r</em>
Expand.
<em>tr </em>+ 120<em>t </em>= 120<em>r</em>
Subtract <em>tr</em> from both sides.
120<em>t </em>= 120<em>r </em>- <em>tr</em>
Factor out the common term <em>r</em>.
120<em>t </em>= <em>r </em>(120-<em>t</em>)
Divide both sides by 120 -<em> t</em>.
= r
Finally, switch <em>r</em> to the left side and you get your answer.
//also, sorry for answering late.. my wifi is poopy//