Find the value of x. Then classify the triangle

Find the solution of this system of equation -7x+y=-20 9x-3y=36

What is the equation of the line in point-slope form? y+ 4 = 1/2(x+4) y-4 = 1/2(x + 4) y-0 = 2(x - 4) y-4 = 2(8-0)

Bob is putting books on a shelf and takes a break after filling 18 1/2 inches on the book shelf. the book shelf is now 2/3 full. how long is the entire bookshelf?