How do you solve the equation by graphing #x^2 - 5x - 24 = 0#?

1 Answer
Nov 23, 2017

Answer:

#x=-3#
#x=8#

Explanation:

The quadratic can be solved by graphing. The solutions are where the graph crosses the x-axis.

graph{x^2-5x-24 [-16.02, 16.01, -8.02, 8]}

As you can see from the graph, it crosses the x axis at #(-3,0)# and at #(8,0)#

The answers are #x=-3# and #x=8#

This can also be solved by factorising the polynomial.

#x^2-5x-24=0#

The factors are 8 and 3 because they multiply to make 24 and subtract to make 8.

#(x+3)(x-8)=0#

This means that the graph crosses the x-axis at #-3# and at #8#.