20× 8 = 160
160 + 2x > or = 500
-160--------------- -160
2x > or = 340
÷2------------÷2
x > or = 170
She has to sell at least 170 cupcakes to make $500 in profit.
Hope this helps!
The fraction is 4/20 for #2.
Move all terms to the left side, and set equal to zero. Then set each factor equal to zero.
n = 5my/m+1