The two negatives cancel out, so it would just mean 1+18, which is 19.
Perpendicular lines have negative reciprocal slop to each other.
So first solve for y.
Slope will be the coefficient of x in y=mx+c form.
m is the slope. Then negative reciprocal this slope and in this case the answer is -1/5
The answer to your question is 0.83
15yd x 18yd = 270yd
That's the area of the object