How would I solve the following equation by completing the Square? x^2-18x+86=0
I just need to know how to solve it, it's Algebra 2 math homework and its on completing the square!
When completing the square, you move the constant to the right side of the equation; in this
case you do that by subracting it from both sides. That leaves the x squared and x terms
on the left side of the equation. Divide the co-efficient of the x term by the co-efficient of the
x squared term. It's easy when the co-efficient of the x squared term is 1. You simply end up
with the co-efficient of the x term. Take half of that and square it.
Add that number to both sides of the equation. You now have to take the square root of both
sides of the equation. On the left side, you will have x plus one-half of the x term. On the right
side perform the addition and take the square root of the result.
In general terms, you will now have something like (x + d) = sqrt (h). d may be negative if the
co-efficient of the x term was negative. Add or subtract d to/from both sides of the equation,
leaving x all by itself of the left side.