solve by using a table:
x^2 - 6x + 8 = 0

Question

solve by using a table:
x^2 - 6x + 8 = 0

anonymous · Answer

what table?

anonymous · Answer

it's a simple quadratic equation

anonymous · Answer

D=b^2-4*a*c
D=36-32=4
x1=(6+sqrt(4))/2=4
x2=(6-sqrt(4))/2=2

mathmate · Answer

Let y=x^2-6x+8
Make the following table
x      y
0      8
1      3
2      0
3      -1
4      0
5      3
....
Locate the roots of equation y=x^2-6x+8=0

anonymous · Answer

Mathmate, Im not sure how to do it can you walk me through it.

mathmate · Answer

The equation you are trying to solve is y=x^2-6x+8=0
So we need to find the values of x such that y=0.
The table is x against y, which means that when x=0, you would substitute 0 for x, such as  y=0^2-6(0)+8=0-0+8=8.
For x=1, we do the same, y=1^2-6(1)+8=1-6+8=3
We continue and complete the table until we find two zeroes (at x=2 and x=4).
This means that when x=2 or when x=4, y=x^2-6x+8=0, which is precisely the solution we're looking for, the solution of the given equation.

anonymous · Answer

oh okay, thank you so much for the explanation

mathmate · Answer

My pleasure!   :)