anyone know the answer to 1=a over 7 minus a over 3? and please tell me how to work it. thanks :)?

Answer 1

first you have to make a/7 and a/3 into 3a/21 and 7a/21 . Then you multiply both sides by 21, which gives you 21=3a-7a, and 21= -4a, a= -21/4

hope i interpreted the question right

Answer 2

if i read your problem correctly you want to solve for a in the equation:

1=a/7-a/3

first you need a common denominator, looks like 21 is the best choice

now rewrite the two fractions with the denominator of 21

1=3a/21 - 7a/21 , note that we haven't changed the value of these fractions, just expressed them a different way

now combine
1=-4a/21

multiply both sides by 21 to get

21=-4a, then divide both sides by -4 to get

-21/4=a

we done, unless you prefer the answer as the mixed fraction:
-5 1/4

Answer 3

1 = (a/7) - (a/3)

21 = 21(a/7) - 21(a/3) ........... multiply both sides by the common denominator

21 = 3a - 7a ........................... 7 goes into 21 three times; 3 goes into 21 seven times. So the denominators are eliminated.

21 = -4a .........................combine the like terms of 3a and -7a

(21/-4) = a ......................to isolate a, divide both sides by -4.

Answer 4

1= a/7-a/3
common denominator =>
(1*3*7)/(3*7)= (a*3)/(7*3) - (a*7)/(3*7)
21/21=(3*a-7*a)/21
3*7=21 wich is not zero
=>
21=3*a-7*a
21=-4a
21+4a=0
4a= -21
a= -21/4
a = -5 -1/4 (fractional)
or
a= - 5.25 (decimal)

Answer 5

you mean
1=a/7-a/3 ?

if so then
21=3a-7a
21=-4a
-(21)/4=a

that was a stupid problem