#1

I'm stuck on a math problem and couldn't find examples of how to do one like this. It's solving an equation by the square root property.

(4x + 1)^2 = 20

(4x + 1)^2 = 20

#2

Math and Science help thread...

#3

see it is as

(4x + 1)^2 = 20

4x + 1 = + or - the square root of 20

4x = -1 + or - the square root of 20

x = -1 + or - the square root of 20 over 4

(4x + 1)^2 = 20

4x + 1 = + or - the square root of 20

4x = -1 + or - the square root of 20

x = -1 + or - the square root of 20 over 4

#4

Math and Science help thread...

Didn't know there was one.

Thanks for being nice about it...

#5

^+1

edit: to the equation guy.

edit: to the equation guy.

#6

see it is as

(4x + 1)^2 = 20

4x + 1 = + or - the square root of 20

4x = -1 + or - the square root of 20

x = -1 + or - the square root of 20 over 4

But that's not entirely it.

x = -1 + or - the square root of 20 over 4

For convenience, I'll just write the above as:

x=-1 +/- (V20)/4

Then we go:

x=-1 +/- (V20)/4

x=-1 +/- (2V5)/4 [I factored a 4 out of the 20, giving us 2 times the square root of 5)

x=-1 +/- (V5)/2 FINAL ANSWER

There ya go.

#7

I think you have to square each term, then add that to the product of the terms doubled. Then it's as simple as solving for x.

But, I haven't taken Algebra in years, so...

But, I haven't taken Algebra in years, so...

#8

Another way to look at (4x + 1)^2 = 20 is (4x + 1)(4x + 1) = 20

So from there, solve for x:

(4x + 1)(4x + 1) = 20

16x + 4x + 4x + 1 = 20

24x + 1 = 20

24x = 19

x = 19/24

...I think...it's been a while....

So from there, solve for x:

(4x + 1)(4x + 1) = 20

16x + 4x + 4x + 1 = 20

24x + 1 = 20

24x = 19

x = 19/24

...I think...it's been a while....

#9

But that's not entirely it.

x = -1 + or - the square root of 20 over 4

For convenience, I'll just write the above as:

x=-1 +/- (V20)/4

Then we go:

x=-1 +/- (V20)/4

x=-1 +/- (2V5)/4 [I factored a 4 out of the 20, giving us 2 times the square root of 5)

x=-1 +/- (V5)/2 FINAL ANSWER

There ya go.

This is right, the other guy was wrong. One question though.

In the final answer, how'd you get 2 as a denominator?

#10

This is right, the other guy was wrong. One question though.

In the final answer, how'd you get 2 as a denominator?

since the 2 is multiplied by root 5, you can reduce it with the 4 on the bottom.

#11

since the 2 is multiplied by root 5, you can reduce it with the 4 on the bottom.

This.

#12

since the 2 is multiplied by root 5, you can reduce it with the 4 on the bottom.

Ah, I was looking at it a weird way. Makes sense now lol.

#13

Another way to look at (4x + 1)^2 = 20 is (4x + 1)(4x + 1) = 20

So from there, solve for x:

(4x + 1)(4x + 1) = 20

16x + 4x + 4x + 1 = 20

24x + 1 = 20

24x = 19

x = 19/24

...I think...it's been a while....

16x^2, broski.

#14

But that's not entirely it.

x = -1 + or - the square root of 20 over 4

For convenience, I'll just write the above as:

x=-1 +/- (V20)/4

Then we go:

x=-1 +/- (V20)/4ACTUAL RIGHT ANSWER

x=-1 +/- (2V5)/4 [I factored a 4 out of the 20, giving us 2 times the square root of 5)

x=-1 +/- (V5)/2 FINAL ANSWER

There ya go.

Close but not quite. You factored too far.

#15

Close but not quite. You factored too far.

You can simplify V20, so yeah, he was right.

#16

16x^2, broski.

This

Its absurdly easy once you remember order of operation. PEMDAS

#17

You can simplify V20, so yeah, he was right.

he forgot to simplify the -1