Asixth grader weighs 90 pounds, which is 120% of what he weighed in fourth grade. how much did he weigh in fourth grade?

Need ! give step by step solutions on how to solve number one [tex]\frac{9-2\sqrt{3} }{12+\sqrt{3} }[/tex] number two [tex]x+4=\sqrt{13x-20}[/tex] number three (domain and range) [tex]f(x)=2\sqrt[3]{x} +1[/tex]

Which is the completely factored from of xy^3-x^3y

The graph represents the gallons of water in a water tank with respect to the number of hours since it was completely filled