If I understand correctly, just substitute 15 for C in f = 1.8c + 32, then solve for F ------------------- f=<span><span>(1.8)(15)</span>+<span>32 </span></span>------------ Simplify f=<span><span><span>(1.8)</span><span>(15)</span></span>+<span>32 </span></span>f = 27 + 32 f = 59 is your answer