HELP with civil engineering hw plz?

It's asking for a distributed load, so the load is w*(10-x). The moment is the integral of the shear force (the distributed load) with respect to x, so the moment is 1/2 w*(10-x)^2. Set that equal to 5 kip-ft and solve for w (set x=0 as you're "cutting" the rest of the beam off from x=0 to get the maximum shear force). Then sub the w back into the shear force w(10-x) to get 1000 lb.