how do I solve for X in: (x + 1)^.8 = 5?

Question

ok jay, that is an exponent, not a multiplication symbol, so the stupidity lies within yourself. k thx.


and that is a point 8 (.8) exponent.

ok, i thought about doing the .8th root of both sides, but i dont remember how to do that in a TI-89, so is there some way of doing a log or something?

Answer 1

is it 8 or 0.8 ,any way i'll solve it as it is 0.8 and u can change it if it was 8 .
(x +1)^.8 = 5
ln(x+1)^.8 = ln (5)
.8 * ln(x+1) =ln (5)
ln(x+1) = ln(5)/.8 = 1.61/.8 =2.01
x+1=e^2.01=7.46
x=7.46 -1 =6.46

Answer 2

ok... u have to change that decimal into a fraction i think.... 0.8 = 8/10 = 4/5

gosh i forgot what ur supposed to do after that....?

(x+1)^4/5 = 5

let me look it up online and see if i can find anything.. brb

ok here's the formula: A fractional exponent — specifically, an exponent of the form 1/n — means to take the nth root instead of multiplying or dividing. For example, 4^(1/3) is the 3rd root (cube root) of 4.

5√(x+1)^4 = 5

now can't u square both sides?

25(x+1)^4 = 25

(x+1)^4 = 1

now i'm just guessing, but doesn't the answer x = 0....??? so that x = 0, x+1 = 1, 1^4 = 1.

i dunno..good luck!

Answer 3

Isolate x by taking the 4/5 root (.8 == 4/5) and subtracting 1.

so the most accurate answer is the (fifth root of 625)-1.

Answer 4

Procedure:

- take the log on both sides of the equation
ln((x+1)^.8) = ln(5)
- apply the log law that state that a log of a quantity to a power is just a multiplication
- 0.8*ln(x+1) = ln(5)
- Divide both sides of the equation by 0.8
- ln(x+1) = ln(5)/0.8 = 2.0118
- take the exponent on both sides of the equation
exp(ln(x+1)) = exp(2.0118)
- the exponent of a log of a quantity reduces to the quantity
(x+1) = 7.4768
solve for x

x = 7.4768 -1 = 6.4768

Good Luck

Answer 5

is that . before the 8 supposed to be there? is it (x+1)^8 or (x+1)^0.8?

Answer 6

stupid, dvide 5 by .8 then -1 from the answer, === 5.25
nvm im a retard i 4got wut carrot top stood 4............. sily me soz..