5x + 1 = 21
2007-07-11 19:56:20 · 26 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
5x=1=21
5x=21-1.. ( you transpose 1 to the rigth side.. it becomes negative because of the revision of sign.)
5x=20 (divide both sides by 20 to get the value of x)
\5 \5
5 will be cancell out, and 20 divided to 5 is equal to 4..
so x=4
2007-07-11 20:07:18 · answer #1 · answered by ○♫mhytzhe○♫ 4 · 1⤊ 1⤋
5x + 1 = 21
Simplify:
5x = 21 - 1
5x = 20
x = 20 / 5
x = 4
Proof (substitute x with 4 in the problem):
5(4) + 1 = 21
20 + 1 = 21
21 = 21
2007-07-15 13:08:02 · answer #2 · answered by Jun Agruda 7 · 2⤊ 0⤋
= 5x + 1 = 21
=5x +1 -21 = 0
= 5x -20= 0
= 5x=20
= x=20/5
= x=4
Ok,this is the method to answer this question.Try better on your studies and if dont know, just post it on YahooAnswers. Well Done
2007-07-12 04:29:28 · answer #3 · answered by Spiderboy 2 · 0⤊ 0⤋
X = 4
2007-07-12 03:06:29 · answer #4 · answered by rajesh k 1 · 0⤊ 2⤋
x = 4
2007-07-12 03:31:06 · answer #5 · answered by rosie recipe 7 · 0⤊ 1⤋
4
2007-07-12 03:11:21 · answer #6 · answered by junior 1 · 0⤊ 2⤋
5x + 1 = 21
5x = 21 -1
5x =20
x = 20/5
x = 4
2007-07-12 03:10:51 · answer #7 · answered by Emad $h 1 · 1⤊ 1⤋
Alright, let me make this as simple as possible:
5x +1 = 21
This is an equation, so if the left hand side is equal to the right hand side. Thus, if you add or subtract something from both sides, they will intuitively still be equal. In this case, you want to subtract 1 from both sides. In context:
5x +1 -1 = 21 - 1
This is then simplified to 5x = 20, right?
Now, what we said about adding or subtracting the same thing from both sides, is the similar to multiplying or dividing both sides by the same number.
In this case, we want to get the value of x, and so we divide both sides by 5. This means:
(5x)/5 = 20/5
The two fives on the left side cancel out, and then 20 divided by 5 gives us 4 on the right side.
Therefore, x=4.
Hope this helped.
2007-07-12 03:35:04 · answer #8 · answered by Apostoli 2 · 0⤊ 1⤋
5x + 1 = 21
5x = 21-1
5x = 20
x = 20/5
x = 4
2007-07-12 02:59:41 · answer #9 · answered by Shamus 2 · 2⤊ 1⤋
x=4
2007-07-12 02:58:53 · answer #10 · answered by cw684 2 · 0⤊ 2⤋