Big Ideas Math Integrated I, 2016
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Big Ideas Math Integrated I, 2016 View details
5. Solving Equations by Graphing
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Exercise 19 Page 247

Create functions from the left-hand and right-hand sides of the equation.

No solution

Practice makes perfect
To graph the equation - x-5=- 13(3x+5), we will create two functions out of the left- and right-hand sides of the equation. f(x)=- x-5 and g(x)=-1/3(3x+5) The x-coordinate where the graphs of these functions intersect is the solution to our equation. Since one of the given equations is not in slope-intercept form, let's rewrite it so that it will be easier to identify its slope and y-intercept.
g(x)=-1/3(3x+5)
g(x)=- x-5/3
Now let's graph these lines.
Point of intersection
We can see that the lines are parallel. Therefore, the graphs do not have a point of intersection. We can verify this algebraically by solving the equation.
- x-5=-1/3(3x+5)
- x-5=- x-5/3
- 5≠-5/3 *
Solving the equation resulted in a contradiction, because - 5 can never be equal to - 53. Therefore, the equation has no solution.