help with practice problems!

[speeddypat]

Hey all, so i feel stupid for asking about these problems because i can do the others just fine...

x/4 + X =
x - x/2 =

the first answer (according to the arco book) is 5x/4, and the second is 4x. I found a couple things wrong in arco, is this one of them or am i just having a major brain collapse?

 

[BackOrdered]

Hey all, so i feel stupid for asking about these problems because i can do the others just fine...

x/4 + X =
x - x/2 =

the first answer (according to the arco book) is 5x/4, and the second is 4x. I found a couple things wrong in arco, is this one of them or am i just having a major brain collapse?

If I'm not mistaken:

x/4 + X = x/4 + x/1 = 5x/4

Still thinking about the last one....

 

[mmx1]

(x/4) + (x) = (x/4) + (4x/4) = (x+4x)/4 = 5x/4

x - (x/2) = (2x-x)/2 = x/2

 

[akpswim]

hey there,

with the first problem you basically have x/4 + x/1 and so if you're adding you need to have common denominators. So 4 would be your common denominator so it would become x/4 + 4x/4 and that's how you get your 5x/4.

With adding and subtracting fractions always make sure you have a common denominator and just multiply the numerator by the common denominator (you multiplied x by 4 to get 4x because 4 was your common denominator)

Hope this helps!

Although the second one confuses me because 2 would be your common denominator so you'd have 2x/2 - x/2 which would equal x/2 so I don't know about that one. Maybe I'm doing something wrong?

 

[TheBubba]

look at it this way... for the x-x/2... make x = 1. the you have 1 - 1/2, which is 1/2. now replace the 1 with the x and you have x/2.

or, you could say that any number minus it half equals its half. and half of x is x/2.

unless its (x-x)/2, which then equals 0. I can think of no way that problem could equal 4x.