Question

Please help (: Thank you !

For questions 1 & 2, add or subtract?

1. (8x - 2y) + (3x - 4y)
a) 11x + 8y
b) 4x - y
c) 11x - 6y
d) 5x + 2y

2. (y + 3d) - (-9y + 7d)
a) -10y + 4d
b) -8y + 10d
c) 8y - 6d
d) 10y - 4d

Answer 1

1 is a simple gathering of terms. Be careful on 2. You are subtracting EVERYTHING in the parentheses.

Answer 2

1) combine like terms
2) distribute that '-' sign into the parenthesis first...then add the 2 equations

Answer 3

Yeah, I still remember from when you helped last time (: But on the first one, since its a '-' sign do I subtract ?

Answer 4

Or is it visa versa, meaning since its minus, I add?

Answer 5

you have to collect the coefficients , for example, related to the variable "y". you must add them up. the coefficients are (-2) and (-4). Sum: (-2)+(-4) = -2-4 = -6.

Answer 6

this means that in the answer, the coefficient of the variable y is -6.

it's done like that: \(\text{stuff} -2y + \text{stuff} - 4y = \text{stuff} + \text{stuff} +(-2-4)y = \text{stuff}+\text{stuff}-6y\).

Answer 7

So the answer is 11x - 6y? Or did I do that wrong?

Answer 8

you're right.

Answer 9

Thank you :)