# what is X

• May 12th 2009, 07:30 AM
andyboy179
what is X
i have a question but i have to work it out in a certain way i will do and example first.

example

2X +3=35

- 3 - 3

2X=32

/ 2 / 2
X=16

real question

4(X+1)=20 i need it like the other question if u don't get how to do the workings out from above just let me know thanks alot
• May 12th 2009, 07:41 AM
HallsofIvy
Quote:

Originally Posted by andyboy179
i have a question but i have to work it out in a certain way i will do and example first.

example

2X +3=35

- 3 - 3

2X=32

/ 2 / 2
X=16

real question

4(X+1)=20 i need it like the other question if u don't get how to do the workings out from above just let me know thanks alot

First go ahead and do the calculations on the left:
4x+ 4= 20. NOW do what you did before.
• May 12th 2009, 07:45 AM
andyboy179
Quote:

Originally Posted by HallsofIvy
First go ahead and do the calculations on the left:
4x+ 4= 20. NOW do what you did before.

do u mean 4x + 1=20
• May 12th 2009, 08:02 AM
HallsofIvy
Quote:

Originally Posted by andyboy179
do u mean 4x + 1=20

No, I do not. The distributive law: a(b+ c)= ab+ ac. 4(x+ 1)= 4(x)+ 4(1)= 4x+ 4.

Suppose x were equal to 2. 4(2+ 1)= 4(3)= 12 while 4(2)+ 1= 8+ 1= 9.
• May 12th 2009, 03:09 PM
stapel
Quote:

Originally Posted by andyboy179
4(X+1)=20

Divide both sides by 4.

Subtract 1 from both sides.

(Wink)