What is the answet to this problem

Solve 13 + w/7= -18 (w/7 is a fraction)

If a distance of 75 yds is measured back from the edge of the canyon and two angles are measured , find the distance across the canyon angle acb = 50° angle abc=100° a=75 yds what does c equal?

Find the vertex for the parabola given by the function ƒ(x) = −3x2 − 6x.