# Rational Expression

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14 ÷ 2 = 7 Remember from arithmetic that in division you can prove the answer is correct

by multipling the answer by the divisor. If the answer from this multiplication is the dividend then you have

divided correctly. Hence 2 x 7 = 14 and thus we divided correctly.

In our system of mathematics if a number is multiplied by 0 the answer is always zero.

Why does this preclude us from dividing by zero?
answer

1/t is called a rational expression.
t = all real numbers except t ≠ 0

This is another example of a rational expression. What values can r and t be?

answer

In general mathematical symbolism rational expressions are defined E/G where E and G are polynomials

and G ≠ 0

Which means that the variables in the denominator cannot be replaced by values that make the denominator zero.

Hence in the above example t cannot equal 3

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