Basic equation problem
I have a problem with this REALLY BASIC equation....
(x+3)/2=5/4
I easily solved it with a calculator and I got x=-0.5 but then I found out something... If I remove the +3, then X will equal 2.5 which makes absolutely no sense at all, note that, I need to do that way where I show all the steps cause my teacher always asks for that but... I have no idea how it turned to -0.5 so I cannot solve it, I always get 5.5 which is a reasonable answer at least.
Can someone explain please? Thank you.
November 17, 2013
3 Comments • Newest first
I am very thankful to you guys, I expected trolls to come really....
Thanks a lot and have a nice day
(x+3)/2 = 5/4
Lowest common denominator = 4
therefore multiply (x+3)/2 by 4 which gives 2(x+3). Because LCD is 4. So you're multiplying each side by 4. [b]Note:[/b] You'll prob wonder why it wasn't 4(x+3), and that's because we divded the LCD 4 by 2 which was at the bottom of that part of the equation.
Now do the same for 5/4. Multiply it by 4 to get rid of the 4. We get 5
Gives us 2(x+3) = 5
2x + 6 = 5
2x = -1
x = -1/2, which is -0.5
The way i would solve this is to.
1) Multiply 4 to both sides to eliminate the /4 as the denominator.
2) You are left with 2(x+3) = 5
3) Expand it. leaving 2x + 6 = 5
4) move the +6 to the right hand side. Making 2x = -1
5) Divide 2 to both side to make x alone. leaving x = -1/2