Algebra Help!!!!! ASAP!?
ok, please help me. I've got an assignment due monday and my teacher sucked at explaining it. it is about adding and subtracting expressions. for ex.
(2a-1) - (-5a-5)
are you supposed to turn the minus sign in the middle to a plus sign and then change all the sign of each term in (-5a-5)? then do you write it out like this?
(2a +5a) + (1+5)
and would the answer be 7a + 6 ???
if i'm wrong please tell me how and be clear on the directions. i'm only in 7th grade.
2007-09-28 14:17:31 · 9 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
What you said is correct but it probably isn't helping you by thinking about it that way. For example
with 2(-5a-5) you would distribute the 2 and you would get (-10a-5), correct?
So try to imagine the - in -(-5a-5) as a -1 and just distribute a -1.
So if you were to write it out again you would write:
(2a-1) + -1(-5a-5)
What you did was distribute the - into the first factor which is wrong. The real answer would be:
(2a-1) + -1(-5a-5)
2a - 1 + 5a + 5 = 7a + 4
2007-09-28 14:24:29 · answer #1 · answered by msc44 2 · 3⤊ 0⤋
Well no, but you have the right idea.
you see when dealing with an equation such as this.
you only distribute the middle sign to the end equation.
so: (2a-1)-(-5a-5)
= (2a-1)+5a+5
= 2a-1+5a+5
= 7a+4
There are many ways to solve these types of eqations.
I just believe this is the easiest and fastest way
Hope I was able to help!
2007-09-28 14:28:46 · answer #2 · answered by taz 2 · 0⤊ 0⤋
This used to give me problems too. I'm not so good at explaining, but I can show you my steps:
(2a-1) - (-5a-5)
2a - 1 + 5a +5 (the negative sign outside turns the negative signs inside into positive signs, you can also take away the parentheses now)
Then you add the variables together (2a +5a) and add the numbers together (-1 +5) and you get
7a +4
What you did was when you switched the numbers in the parentheses around you dropped the negative sign in front of the 1.
Hope this helps.
2007-09-28 14:34:01 · answer #3 · answered by Anonymous · 0⤊ 1⤋
I have 7a + (-6) You add the opposite of the subtraction problems and it doesn't matter what order you add in. 2a+-1+5a+-5= 2a+5a+-1+-5=7a + -6
2007-09-28 14:33:49 · answer #4 · answered by Nate 2 · 0⤊ 0⤋
the - sign outside the bracket may be considered as multiplying by - 1:-
2a - 1 - 1 (- 5a - 5)
2a - 1 + 5a + 5
7a + 4
2007-10-01 04:51:21 · answer #5 · answered by Como 7 · 1⤊ 1⤋
(2a-1)-(-5a-5)=0
2a-1+5a+5=0
7a +4=0
7a =-4
a=- 4/7
a= - 0.6
2007-09-28 14:29:23 · answer #6 · answered by Freesia 5 · 0⤊ 0⤋
I'm really good at solving Algebra problems. Just tell me ur problems!!
2016-04-06 06:08:43 · answer #7 · answered by Anonymous · 0⤊ 0⤋
Youre Right! I Think!
2007-09-30 02:25:14 · answer #8 · answered by ExpressYOURSELF! :) 5 · 1⤊ 0⤋
I think your right.
2007-09-28 14:29:00 · answer #9 · answered by Peterbattahoggabatta 5 · 0⤊ 0⤋