simplify 2x-4y-3(7x-2y)

Question

solomonzelman · Answer

$$2x-4y-3(7x-2y)$$

solomonzelman · Answer

what is   -3(7x-2y) 

expand!

solomonzelman · Answer

need help on that?

anonymous · Answer

not sure... i though x and y couldnt go into eachother neither can 3 go into x or y

solomonzelman · Answer

I am not saying to subtract multiply each number in (7x-2y) by '-3' and tell me what you get, OK?

anonymous · Answer

7 time -3 is -21 and 2 times 3- is -6

solomonzelman · Answer

yeah, but isn't it 7x time -3 is -21x  and 2y times 3- is -6y?

anonymous · Answer

oh yeah

anonymous · Answer

sooo its -21x and -6y? i still dont get how that is going to help...

solomonzelman · Answer

yep so it is -21x and -6y   OR -21x -6y right?

anonymous · Answer

i guess, but what about 2x-4y do you just add those in?

solomonzelman · Answer

yes, put  -21x -6y   in front of   2x-4y,
since -21x -6y = -3(7x-2y)    [except that -21x -6y is the expanded form.)
so you add  -21x -6y in, instead of  -3(7x-2y)

simply just put -21x -6y  in front of   2x-4y,

write it out for me please....

anonymous · Answer

-21x -6y (2x-4y)

anonymous · Answer

oops i forgot to type +

solomonzelman · Answer

what?! -21x -6y (2x-4y), noooooo 
-21x -6y is in front of 2x-4y

wouldn't it be $$2x-4y-21x -6y$$  ? right?

solomonzelman · Answer

(Sorry for confusing you)

anonymous · Answer

oooh i see. then would it be 23x-10y?

solomonzelman · Answer

No!

solomonzelman · Answer

Think!

anonymous · Answer

O_O

solomonzelman · Answer

so what is it?

solomonzelman · Answer

like terms.......................

anonymous · Answer

19x-4x? crud i'm boody confused

anonymous · Answer

i meant 4y

solomonzelman · Answer

you have 2x-4y-21x-6y

what are the like terms, do you know?

anonymous · Answer

no...

solomonzelman · Answer

2x-4y-21x-6y

what if you switch the second term (-4y) with the third (-21x) ?

anonymous · Answer

sooo -19x-(-4y)?

solomonzelman · Answer

Hold on, just show what would it look like if you  switch the second term (-4y) with the third (-21x) ?

solomonzelman · Answer

(In this case) switch 4y with 21x, OK?

anonymous · Answer

2x-21x-4y-6y

solomonzelman · Answer

Yep! and what's the answer?

anonymous · Answer

-19x-(-2y)

solomonzelman · Answer

the -19x is right!

solomonzelman · Answer

How do you get -(-2y)?

-4y-6y= ?

anonymous · Answer

i subtracted 6 from 4,  4-6

solomonzelman · Answer

it is -4y and -6y
so -4-6 not 4-6

anonymous · Answer

soo -10y?

solomonzelman · Answer

Yes!
and as you said -19x, so what is the answer?

anonymous · Answer

it would be +6y since the -3 distributes in

anonymous · Answer

-19x-(-10y)

solomonzelman · Answer

@BethanyK is right!
it is +6y, and therefore -19x+2y.

anonymous · Answer

wait is it -19x+2y or is it -19x-(-10y)?

solomonzelman · Answer

I am sorry for misleading, if not her.... really, my bad!

solomonzelman · Answer

!st!

anonymous · Answer

i'm really confused now O_O