Question 862451: Please help my daughter solve the following:
x^2-4=0
We must solve for x and y.
Answer by josgarithmetic(39621)   (Show Source):
You can put this solution on YOUR website! Tell her to try doing this:
Perform the multiplication, (x-a)(x+b). Simplify and put into the form of decreasing powers of x. Notice that this will be a trinomial with leading term of x^2.
Perform the multiplication, (x+a)(x+b). Simplify, and do as before... Compare the two different products.
Perform the multiplication, (x+a)(x+a). Simplify, and as before, arrange into decreasing powers of x.
LASTLY, perform the multiplication, (x+a)(x-a). Simplify this. She now has a formula for the difference of two squares. YES, YES, YES. This will help to solve for x in x^2-4=0, because now the quadratic expression can be factored. One or the other factors must be zero. Not both at the same time. Only one of them at a time.
Note carefully, x^2-4=0 has no "y". It only has variable x.
|
|
|
