Final answer:
The question deals with linear and quadratic functions, with solutions to the quadratic equation found using methods like factoring or the quadratic formula. Quadratic functions can have two possible solutions due to their parabolic shape.
Step-by-step explanation:
The student's question involves the equations of two mathematical functions, r(x)=2x+2 and s(x)=x²+4x, which require an understanding of how to work with linear and quadratic equations. The function r(x) is a linear function, while s(x) is a quadratic function. Quadratic equations are second-order polynomials and have the general form ax²+bx+c=0. To find the solution of quadratic equations, we often use factoring, completing the square, or the quadratic formula, which is x = (-b ± √(b² - 4ac)) / 2a. It is important to note that a quadratic equation can have two solutions, as it represents a parabola that can cross the x-axis at two points.