Checkboxes 1,2,5 are correct. hope it helps
The answer is left two places.
For example 5.% would be 0.05 as a decimal.
Look up online "equation calculator" and it should be the first one to appear, "Symbolab" supper easy way to help you with problems!
Only one because there is one variable and the combined coefficients of x are non-zero.
(0.75(x+40)=0.70(x+20), 0.05x=14-30=-16, x=-320)
Find Total weight at left side

Now
Per block weight at right side
