X+2y=12
-x=-y-6
how do you solve using substitution method

What are the sotions to the quadratic equation 9x^2=4

What is the slope of the line that contains the points (-2,1) and (0,-3)

The area (a) of a circle with a radius of r is given by the formula and its diameter (d) is given by d=2r. arrange the equations in the correct sequence to rewrite the formula for diameter in terms of the area of the circle.