Advertisement

Check it out:

Do the first chunk of the problem WITH the dummy guys:

( x^3 + 0x^2 + 0x - 8 ) / ( x - 2 ) ... the first term in the answer is x^2 ... multiplying to ( x - 2 ) gives ( x^3 - 2x^2 ) ... subtracting gives 2x^2 ... you need an x^2 guy to stick the -2x^2 under!

If you didn't have the dummy guy:

( x^3 - 8 ) / ( x - 2 ) ... the first term of the answer is x^2 ... multiplying to ( x - 2 ) gives ( x ^3 - 2x^2 ) ... without an x^2 term in the dividend, it is very confusing to subtract

Try working the rest of the problem the right way. I'll do it on the next page.

after subtracting from the first term and bringing down, we have 2x^2 + 0x ... dividing gives 2x ... multiplying to ( x - 2 ) gives ( 2x^2 - 4x ) ... subtracting and bringing down gives ( 4x- 8 ) ... dividing gives 4... multiplying gives ( 4x - 8 ) ... subtracting gives 0! so, the final answer is x^2 + 2x + 4

So,

( x^3 - 8 ) / ( x - 2 ) = x^2 + 2x + 4


YOUR TURN:

( 8x^3 - 1 ) / ( 2x - 1 )