Math help pretty please?-Collection of common programming errors

1. Find all numbers for which the rational expression is undefined. If the rational expression is defined for all real numbers so state 5x over 3x-12 2. Find all numbers for which the rational expression is undefined. If the rational expression is defined for all real numbers so state.

x+5 over x^2+x-42

1. 1. 5x/(3x-12) is undefined when 3x-12 = 0. So, when x=4, this is undefined! 2. (x+5)/(x^2+x-42) is undefined when x^2+x-42=0. x^2+x-42=0 (x+7)(x-6)=0 x=-7,6

   So it is undefined when x=-7 or x=6!

2. 1. When finding when a fraction is undefined, it doesn’t matter what the top of the fraction is. A fraction is undefined when the bottom is 0. This is because it’s impossible to divide by 0. Therefore, you have to find when 3x – 12 = 0. This is just a simple algebra problem. 3x – 12 = 0 3x = 12 x = 4 The fraction is undefined when x = 4 2. Same thing as the last one. You only have to pay attention to the bottom of the fraction. x² + x – 42 = 0 x² – 6x + 7x – 42 = 0 x(x-6) + 7(x-6) = 0 (x+7)(x-6) = 0 When either of these equals 0, then the equation is true because they are multiplied. Therefore, when x = -7 or when x = 6 the equation is true.

   The fraction is undefined when x is either of these values.

3. 1. it’d be (5x)/(3x-12) you cannot divide by zeros so simply set the denominator equal to zero and solve. 3x-12=0 3x=12 x=4 2.(x+5)/(x^2+x-42) do the same as the last problem x^2+x-42=0 factor (x+7)(x-6) x+7=0 x-6=0 x=-7 x=6

   so your answers are 6 and -7

4. Simply the denominator should be different from zero in the first case x is different from 4 in the second (X-6)(x+7)is different from zero, so x is different from 6 and -7

Originally posted 2013-11-09 21:09:56.