To simplify the expression 3x + 2y – 5x + 8y?

Hi Climaticsman, it is so important question that you have posted. In mathematics especially in algebra the sign just in front of a symbol or number is possessed by that symbol. ie - 3 , now 3 has negative sign. In case - 5 + 4, 5 does not have + sign, + sign is for 4 and in no way the sign that follows a symbol belongs to that symbol.

So in this example 4x - 5y + 4x^3 - 7x^2 - (a+b)

4x^3 has + sign. (a+b) term has - sign. 4x would have + it is understood though that sign is not mentioned there.

So as we consider the expression given by you, we rearrange +3x, +2y, -5x, +8y (separated as individual compartments just in case of a train)

Now rearranging them with an intention of collecting like terms, 3x - 5x +2y + 8y

If we need to put them in collected form of like terms, then we use parenthesis.

So (3x-5x)+(2y+8y) as if +1 has been taken as common factor.

Suppose if the given is of this form, 3x-2y-5x+8y then we take -1 as common factor so we write

(3x-5x)-(2y-8y)

So this time we have - sign in front of the parenthesis.

Look all they did was change the order of what was written ...... it is like they took

# @ % & and rearranged them like

# % @ & but they also added these things called Parentheses so like

(# %)+(@ &) this will always be the case since each symbol keeps its original sign so it could have been

-# -@ -% -& and that will go to

(-#-%)+(-@-&)

hope that helps if you need the next step it is just adding the numbers together so it will be

3x-5x = -2x and 2y+8y=10y but you write them together still like

(-2x)+(10y) or you could have worte -2x+10y or 10y-2x when everything is added you can move stuff around but they stay attached to the sign that is in frount of them GOOD Luck!

4x²-8y+3x-9x²+10y = grouping common terms: (4-9)x²+(-8+10)y+3x = -5x²+2y+3x -> C

3x + 2y – 5x + 8y = 3x - 5x + 2y + 8y = -2x + 10y

As we can imagine that after plus sign there is a 1 & we multiply the result we get 2y plus 28..which is given in the expression..! so it satisfies it.

because the 2y is positive

its a + because if it was negative it would give -10y in total which is clearly not true because its supposed to be +10y in total