-3/7x=-21 what does x equal?

Answer 1

is your question (-3/7)x = -21?
if so, when you need to isolate x and its coefficient (number multiplied to it) is a fraction, you simply multiply by its reciprocal (flip it over). (-3/7) (-7/3) = 21/21 = 1
remember, when working with an equation, whatever you do to one side, you must do to the other. so...
(-3/7)x = -21
(-7/3) (-3/7)x = -21 (-7/3)
1x = +7(7)
x = 49
Now...remember to always check you work...plug 49 back in
(-3/7)x = -21
(-3/7)49 = -21 ....so this is 3*49/7 and 49/7 is 7 so
-3(7)= -21
and -21 = -21 so x=49

Answer 2

Ouch! some of these answers scare me ! This is a simple multiplication problem. Don't let the variable (X) and the signs fool you.
-3/7 is a factor
X is the other factor
-21 is the product.
Fractional co-efficients are Always written seperate from their variable. so you have -3/7 X with -3 as the numerator, and 7 as the denominator.
The problem is asking you to solve for the variable.E-Z enuff.
Take the known product (-21) and divide by the known factor (-3/7)to reveal the other factor. Turn -21 into a fraction from the whole number. -21 becomes -21/1. divide by -3/7
-21/1 div by -3/7
flip 2nd fraction and multiply :
-21/1 * -7/3
Multiply across
-21/1 * - 7/3 = 147/3
or cancel to reduce to lower terms
(done by dividing 3 into 3&-21)
-7/1 * - 7/1 = 49/1 OR 49
neg. times neg. gives a pos. result

Answer 3

Solve for "x"... - 3/7x = - 21

First: eliminate the fraction - multiply the denominator with everything....

(7x)(- 3/7x) = (7x)(- 21)

Sec: cross cancel "like" terms & combine the remaining terms...

- 3 = - 147x

Or, -147x = - 3

Third: isolate "x" on one side - divide both sides by -147...

-147x/-147 = - 3/-147

x = 3/147

*Simplify the fraction into lowest terms...

x = 1/49

P.S. The result doesn't need to be in decimal form, unless your teacher asks you to do so.

Answer 4

Multiply -7/3 from both sides:
x=-21(-7/3)
x=49

Check:
-3/7(49)=-21
-3(7)=-21
-21=-21

Answer 5

since only one side is a fraction, you must try to equate so that both sides are not a fraction, you can undo that by multiplying 7 or -7 if you wish to do less work...here is how it goes...
-3/7x = -21
3x = 147 -->you can get this by multiplying both sides by -7
divide both sides by 3 to isolate x
x = 49
now you can check the answer by plugging in the x into the equation
-3/7 (49) = -21
-21 = -21 checks out, and you can confirm that your answer is indeed
x = 49

Answer 6

x= -49

you try to get the X alone so you do the reciprocal of -3/7 which is 7/-3.
and then you multiply 7/-3 to -21.
You get - 49.

Answer 7

Play with it. Try multiplying the 7x out of the left side and see what you get. You won't be done, but it'll make that icky fraction look better.

Hope it helps,
Lee

Answer 8

You can set up a proportion to answer this: -3x/7 = -21/1.
Cross-multiply, which yields this: -3x(1) = -21(7)
Cleaning this up: -3x = -147
Divide by -3: x = 49

Answer 9

x = 49
or
x = 1/49
depending on how you interpret -3/7x

Answer 10

-3/7x = -21
x = (-21) / (-7/3)
x = (-7) * (-7)
x = 49