49^x= 343

[adamRB12]

?

 

[JDrake]

1.5

 

[RapidSnail]

7?

 

[Injury]

Guess and check works.

49^1 = 49, 49^2=2401...

go right in between just to get an idea... 49^1.5=343=bingo.

 

[adamRB12]

but how did u get that answer?

 

[JDrake]

Originally posted by: adamRB12
but how did u get that answer?

Can you use graph paper?

 

[StrangerGuy]

At first glance x must be greater than 1 and less than 2.

EDIT:

49^x = 343
7^(2x) = 7^3
2x = 3
x = 1.5

 

[6000SUX]

Originally posted by: adamRB12
but how did u get that answer?

343 / 49 = 7

7 is also the square root of 49, or 49 ^ .5

 

[Epic Fail]

you add the first and last digit, then divide that by the middle digit, (3+3)/4 = 1.5

elementary math ftw

 

[Tiamat]

49^x = 343
10^x = 31.6227766017 (through hand division)
log 10^x = log 31.6227766017
x = 1.5 (using slide rule)

 

[imported_LoKe]

Originally posted by: 6000SUX

Originally posted by: adamRB12
but how did u get that answer?

343 / 49 = 7

7 is also the square root of 49, or 49 ^ .5

Exponant, not multiplication.

49^x != 49x

 

[Reikon]

x = ln343 / ln49

Pre-calc, so I met your requirement.

 

[MageXX9]

If I had to do it in my head, I would have done, 7 X 50 - 7 = 343.

For some reason, that's how I approached it, I guess because I could multiply 7 X 50 very quickly.

 

[6000SUX]

Originally posted by: LoKe

Originally posted by: 6000SUX

Originally posted by: adamRB12
but how did u get that answer?

343 / 49 = 7

7 is also the square root of 49, or 49 ^ .5

Exponant, not multiplication.

49^x != 49x

Well, duh. So 49^1 X 49^.5 = 49^1.5 . You misunderstood me, but I understood the OP and provided a shortcut way of arriving at the answer.

 

[imported_LoKe]

Originally posted by: 6000SUX

Originally posted by: LoKe

Originally posted by: 6000SUX

Originally posted by: adamRB12
but how did u get that answer?

343 / 49 = 7

7 is also the square root of 49, or 49 ^ .5

Exponant, not multiplication.

49^x != 49x

Well, duh. So 49^1 X 49^.5 = 49^1.5 . You misunderstood me, but I understood the OP and provided a shortcut way of arriving at the answer.

Oh, sorry. I thought you were trying to say that 7 was the answer.

 

[bonkers325]

49^x = 343

log(49)^x = log(343)

xlog(49)=log(343)

x=log(343)/log(49)

x=1.5

 

[6000SUX]

Originally posted by: bonkers325
49^x = 343

log(49)^x = log(343)

xlog(49)=log(343)

x=log(343)/log(49)

x=1.5

The OP said no calculator (which covers slide rules), and didn't say you could use precompiled computational results such as a log table either.

 

[Lonyo]

By knowing 343 is 7^3 and 49 is 7^2 :x

 

[6000SUX]

Originally posted by: LoKe
Oh, sorry. I thought you were trying to say that 7 was the answer.

No biggie. I was trying to help the OP make a small mental leap, which is the only reason I didn't finish it.

 

[ActuaryTm]

A significant number of the responses in this thread both sadden and frighten me.

 

[bonkers325]

Originally posted by: 6000SUX

Originally posted by: bonkers325
49^x = 343

log(49)^x = log(343)

xlog(49)=log(343)

x=log(343)/log(49)

x=1.5

The OP said no calculator (which covers slide rules), and didn't say you could use precompiled computational results such as a log table either.

log[base49](343)=x

log[base49](49*7)=x

log[base49](49)+log[base49](49^0.5)=x

1+0.5*1=x

1.5=x

there you go

 

[Legendary]

Originally posted by: StrangerGuy
At first glance x must be greater than 1 and less than 2.

EDIT:

49^x = 343
7^(2x) = 7^3
2x = 3
x = 1.5

 

[hypn0tik]

Originally posted by: Legendary

Originally posted by: StrangerGuy
At first glance x must be greater than 1 and less than 2.

EDIT:

49^x = 343
7^(2x) = 7^3
2x = 3
x = 1.5

 

[TecHNooB]

Originally posted by: hypn0tik

Originally posted by: Legendary

Originally posted by: StrangerGuy
At first glance x must be greater than 1 and less than 2.

EDIT:

49^x = 343
7^(2x) = 7^3
2x = 3
x = 1.5

That was the 7th post on this topic. How we arrived at page 2 is beyond me ;/

 

[desteffy]

factor 343 ftw