Combining Like terms

~Midnight.Kitten~

Junior Member
Joined
Jun 27, 2005
Messages
87
ok so in combining like terms, what do you do with the ones already combined?

examplLe: 4x+3y+6+9x+2y+1=
4x+9x= 13 x
3y+2y=5y
6+1=7
*what would i do with the 13x,5y, and 7, do i combine them to, like 13x+5y+7= 25xy?
 
~Midnight.Kitten~ said:
or, could I add a 1 in front of every x and y, like 1x + 1y =2xy but just keep the two?
okay, add the opposite to the 13x and 5 y, would -13x and -5y and then multiply the exponents so 1/13x + 1/5y would come out to be just 13 and 5. so it would be -25?¿
 
what would i do with the 13x,5y, and 7, do i combine them to, like 13x+5y+7= 25xy?

Well, see if it works. plug in some numbers for x and y, say x = 2, y = 3. The left side is:

13x + 5y + 7
= 13(2) + 5(3) + 7
= 26 + 15 + 7
= 48

The right side is:

25xy
= 25(2)(3)
= 50(3)
= 150

So 13x + 5y + 7 is not the same as 25xy.
 
Yes.

25xy means 25 * x * y, and I just replaced x with 2 and y with 3, so I got 25 * 2 * 3, which is 150.
 
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