Simplifying Algebraic Fractions: Difference of Squares

Transcript
Okay! So first of all, I took out the common factors for anything that I can. So here! See how x squared is common. So I took the x squared out and here, 16. We know that 16 is 4 squared. So this will be a difference of two squares.
So I’ve simplified it, like that. Now! Let’s use our cross method for the denominators, so you can see that one I’m going to use 4 which becomes 4x, and 5 which becomes 5x. Add them! We get 9x which is exactly what we want.
Now for this one, I’m going to use my x and x again. Now it’s negative, so I’m going to use positive and negative. So one’s going to be positive 3 and the other one will be negative 4, so negative 4x. And 3 minus 4x is negative x which is what we want. So now replace them all back into the denominators like that.
See how that one, I just left it as it is, and see how x squared minus 4 squared that’s x plus 4x minus 4, the difference of 2 squares and here, x plus 4, x plus 5 on the denominator and same for there, just replace them in. So now it’s my favorite part is to start canceling if anything that’s common. Now you can see that here, x minus 4 is common! Cancel! And you can see here, x plus 3, x plus 3 is common! Cancel! x plus 4, x plus 4, Common! Cancel them all out. So we just have x squared and x plus 5. That is the answer, okay?
So that’s just what’s left, so it’s nice and simple.
Algebra Algebraic Fractions Arc Binomial Expansion Capacity Common Difference Common Ratio Differentiation Double-Angle Formula Equation Exponent Exponential Function Factorise Functions Geometric Sequence Geometric Series Index Laws Inequality Integration Kinematics Length Conversion Logarithm Logarithmic Functions Mass Conversion Mathematical Induction Measurement Perfect Square Perimeter Prime Factorisation Probability Product Rule Proof Pythagoras Theorem Quadratic Quadratic Factorise Ratio Rational Functions Sequence Sketching Graphs Surds Time Transformation Trigonometric Functions Trigonometric Properties Volume
Responses