I need help with adding variables that have negative exponents?

Question

it seems i can not figure out how to add these two variables:

x^-1 + x^-3

your help is greatly appreciated!!!

thanks

Answer 1

You don't need to add them.  Even if they were positive, because they have different exponents, you dont add.  (x^2 + x^3) cannot be simplified any more by addition.

Answer 2

You can't. This is equivalent to 1/x + 1/x³. If you really want to combine into a single fraction, then you need a common denominator:

1/x * x²/x² + 1/x³

x²/x³ + 1/x³

(x² + 1)/x³

Answer 3

basically, you cant add/subtract any variables which has different exponents. they have to be the same.

Answer 4

There's not much you can do with this expression. If you want to get rid of negative exponents, try this:

x^-1 + x^-3 = (1/x) + (1/x^3) = (1/x)*(1 + 1/x^2)

= (1/x)*[1 + (1/x)^2]

Answer 5

well x^-1

MEANS

1/x

X^-3

MEANS

1/x^3

SO 1/x+ 1/x^3

means to add you will need to mutiply the left by x^2 to get common denominator of x^3, RIGHT????

x^2/x^3 + 1/x^3

= (x^2+1)/x^3