Please help me? I can't get one wrong, its a 3 question quiz. thank you!

Mindy bought 5/8 pound of almonds and a 3/4 pound of walnuts.which pair of fraction cannot be used to find how many pounds of nuts she bought in all.

The angle of a triangle are given as 6x,(x-3), and (3x+7). find x then find the measures of the angles

Select the point that is a solution to the system of inequalities. y< =-x+3 y=x^(2)-3x