Question

How do I solve radicals??

Answer 1

Your question is too general.  You might ask instead, "how do I simplify the radical sqrt(48)?"

sqrt(48) can b e simplified by rewriting 48 as the product of the perfect square 16 and the not-a-perfect-square 3:

sqrt(48) = sqrt(16)*sqrt(3) = 4*sqrt(3)    (answer)

In #76, rearrange the terms so that you have 3sqrt(7x+4)=15.  Then divide both sides by 3, obtaining sqrt(7x+4) =5.  Squaring both sides:  7x+4=25.
Solve this linear equation for x.