SOLUTION: (x - 10)(x + 10)

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: (x - 10)(x + 10)      Log On


   

Question 118524: (x - 10)(x + 10)
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

%28x-10%29%28x%2B10%29 Start with the given expression



Remember, when you FOIL an expression, you follow this procedure:


%28highlight%28x%29-10%29%28highlight%28x%29%2B10%29 Multiply the First terms:%28x%29%2A%28x%29=x%5E2


%28highlight%28x%29-10%29%28x%2Bhighlight%2810%29%29 Multiply the Outer terms:%28x%29%2A%2810%29=10x


%28x%2Bhighlight%28-10%29%29%28highlight%28x%29%2B10%29 Multiply the Inner terms:%28-10%29%2A%28x%29=-10x


%28x%2Bhighlight%28-10%29%29%28x%2Bhighlight%2810%29%29 Multiply the Last terms:%28-10%29%2A%2810%29=-100


x%5E2%2B10x-10x-100 Now collect every term to make a single expression



x%5E2-100 Now combine like terms


---------------------
Answer:
So %28x-10%29%28x%2B10%29 foils and simplifies to x%5E2-100

In other words, %28x-10%29%28x%2B10%29=x%5E2-100