Sal determines the x-intercept of a linear equation from a graph. Afterwards, he checks his work by plugging values back into the equation.
Intercepts from a graph is a free educational video by Khan Academy.It helps students in grades 8 practice the following standards 8.F.A.3.
1. 8.F.A.3 : Interpret the equation y = mx + b as defining a linear function, whose graph is a straight line; give examples of functions that are not linear. For example, the function A = s^2 giving the area of a square as a function of its side length is not linear because its graph contains the points (1,1), (2,4) and (3,9), which are not on a straight line..