(5x-1)^2=4/25

Question

(5x-1)^2=4/25

anonymous · Answer

5x-1=2/5
5x=7/5
x=7/25

anonymous · Answer

right?

anonymous · Answer

shouldn't it be:  $\large 5x-1=\pm \frac{2}{5} $   ???

anonymous · Answer

Yes. we should include pm... ie plus minus..

anonymous · Answer

ok so can you explain the step by step after sq rooting that you get 3/25 and 7/25 as the answer that is where i get lost

anonymous · Answer

Take the square root both the sides and tell me what are you getting?

anonymous · Answer

i'm getting 5x-1= 2/5, but what do i do after that?

anonymous · Answer

b/c there are 2 answers 3/25 and 7/25

anonymous · Answer

Yes, there will be two answers for this...

anonymous · Answer

Actually, when we take square root of any number we consider plus minus sign with it :

Like :

$$(5x-1)^2 = \frac{4}{25}$$

$$\implies 5x - 1 = \pm \frac{2}{5}$$

anonymous · Answer

Now, firstly you will consider + sign with 2/5   and then in second case you will consider - sign with 2/5

Solve by using + 2/5 first..

anonymous · Answer

For Plus Case :

$$5x - 1 = \frac{2}{5}$$

Solve this for x..

anonymous · Answer

Now Minus Case :

$$5x - 1 = -\frac{2}{5}$$

And now find x in this case..

anonymous · Answer

ok so then do i divided each side by 5?

anonymous · Answer

Firstly add 1 both the sides...

anonymous · Answer

$$5x - 1 = \frac{2}{5}$$
Add 1 to both the sides and tell me what you got?

anonymous · Answer

ok so then i have 5x= 1+2/5 = 5x=3/5

anonymous · Answer

How you got 3/5 ??

anonymous · Answer

$$1 + \frac{2}{5} = ?$$

anonymous · Answer

i just added the 1 to the 2

anonymous · Answer

No, you cannot add 1 to the fraction directly..

Do you know about LCM or LCD ??

anonymous · Answer

oh yes

anonymous · Answer

Then use that...

anonymous · Answer

ok so the lcd would be 5 making the fraction 5/5 correct?

anonymous · Answer

Correct..

anonymous · Answer

ok so adding 5/5 to 2/5 gives you 7/10 am i wrong there

anonymous · Answer

See, you, in LCD, never add denominator, the denominator remains the same..

Just add or subtract the numerator...

anonymous · Answer

ok

anonymous · Answer

$$\frac{5}{5} + \frac{2}{5} = \frac{5 + 2}{5} = \frac{7}{5}$$

anonymous · Answer

thank you now i see where my issues were :)

anonymous · Answer

So, now you got :

$$5x = \frac{7}{5}$$

Now divide by 5 here to get x..

anonymous · Answer

you getr 7/25

anonymous · Answer

Yes...

anonymous · Answer

Now :

$$5x - 1 = -\frac{2}{5}$$

Add 1 to both the sides...

anonymous · Answer

0.28,0.12