What is the slope of this non-vertical line?

Find the number of positive three-digit even integers whose digits are among 9, 8, 7,5, 3, and 1.

Aquadratic equation in standard from is written ax^2= bx+c, where a,b and c are real numbers and a is not zero?

X+y=-4 x-y=2 use elimination with adding and subtraction