2007-11-23 12:25:05 · 10 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
3/7x=15
MULTIPLY both sides by the reciprocal of 3/7 which is 7/3
3/7x (7/3)=15 (7/3)
x = 35 ANSWER
CHECK Substitue x = 35 into the originaal equation
(3/7) (35) = 15
3(35) / 7 = 15
3(5) = 15
15 = 15 it checks out
2007-11-23 12:29:40 · answer #1 · answered by Anonymous · 1⤊ 0⤋
Do you mean 3/(7x) = 15, or (3/7)x = 15?
a. 3/(7x) = 15
First: multiply the denominator with each term.
7x(3/7x) = 7x(15)
SEc: cross cancel the same terms - combine the rest.
3 = 105x, or 105x = 3
Third: divide both sides by 105 (when you move a term to the opposite side, always use the opposite sign).
105x/105 = 3/105
x = 3/105 (simplify)
x = 1/35
b. (3/7)x = 15
7[(3/7)x] = 7(15)
(3)x = 7(15)
3x = 105
3x/3 = 105/3
x = 35
2007-11-23 14:59:45 · answer #2 · answered by ♪♥Annie♥♪ 6 · 0⤊ 0⤋
This isn't the orthodox approach, but it works here: Divide each side by 3. If 3/7x=15, then 1/7x=5. Then multiply each side by 7. 1x=35.
2007-11-23 12:37:57 · answer #3 · answered by aida 7 · 0⤊ 0⤋
3/7x = 15 => x = 15*7/3 = 35 if 3/7x means (3/7)x
3/7x = 15 => 7x = 3/15 => x = 3/(15*7) = 1/35 if 3/7x = 3/(7x)
2007-11-23 12:34:47 · answer #4 · answered by sv 7 · 0⤊ 0⤋
first you multiply both sides by 7, by doing this you get rid of the denominator on the 3/7 side and you get 3x=105. Then you divide both sides by 3. This gives you x=35. To check this you substitute 35 for x in the equation: 3/7 * 35=15(* is what I used for the multiplication sign so it wouldn't be confused with x) then you divide by 35, to get 3/7=15/35 then you reduce to lowest terms by dividing both the numerator and the denominator by 5, to get 3/7 this gives you 3/7=3/7 which shows that the value of x=35 works for this question.
2016-05-25 03:53:30 · answer #5 · answered by ? 3 · 0⤊ 0⤋
this depends on how the question is written,
IF
3 / (7x) = 15 then x = (1/35)
OR
(3/7) x = 15 then x = 35
The location of the variable is very important, remember to check to avoid mistakes.
2007-11-23 12:37:34 · answer #6 · answered by Ry 1 · 0⤊ 0⤋
multiply by teh recipracal of 3/7
so 7/3 times 3/7 cancels it out and 7/3 times 15=
so x= whatever 7/3 times 15 is
2007-11-23 12:32:48 · answer #7 · answered by Anonymous · 0⤊ 0⤋
7/3 multiply be both sides. You get 35. Check it out . 7/3 multiplied by 35 gives you 15.
2007-11-23 12:41:29 · answer #8 · answered by Anonymous · 0⤊ 1⤋
3/7x=15
First, you multiply both sides by 7 and u get:
3x=105
Then, you divide both sides by 3:
x=35
2007-11-23 12:42:04 · answer #9 · answered by Δ□xo 2 · 0⤊ 1⤋
3/7x=15
1/7x=5
x=5x7=35
2007-11-23 13:50:58 · answer #10 · answered by Anonymous · 0⤊ 1⤋