Equations & Parentheses: -3x(x-1)=2(x-8)+3

Takitia

New member
Joined
Jul 11, 2007
Messages
18
-3x(x-1)=2(x-8)+3
-3x+-3=2x-16+3
-3x+-3=2x-19
-2x 2x
-3=19

I have no idea what I have done wrong
 

galactus

Super Moderator
Staff member
Joined
Sep 28, 2005
Messages
7,216
Re: Equations & Parenthesis

Takitia said:
-3x(x-1)=2(x-8)+3
-3x+-3=2x-16+3right here, -3x^2+3x=2x-16+3
-3x+-3=2x-19
-2x 2x
-3=19

I have no idea what I have done wrong
 

Kristy

Junior Member
Joined
Jun 26, 2007
Messages
57
Re: Equations & Parenthesis

Takitia said:
-3x(x-1)=2(x-8)+3
-3x+-3=2x-16+3
-3x+-3=2x-19
-2x 2x
-3=19

I have no idea what I have done wrong
Have you learned about the distributive property yet? If not maybe that's making these problems harder. What the distributive property means is if you have
2(3+6) you do 2*3 + 2*6.
The 2 is distributed.
What if you have negative signs?
Remember that negative * negative = positive.

2(3-6)=2*3-2*6

and here's another one.

2(-3+6) = 2*(-3) + 2 ( 6)

and another, with negative signs everywhere.

-2(-3-6) = (-2)*(-3) + (-2)(-6) = 2*3 + 2*6

Does that help at all?
 
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