+0  
 
0
76
1
avatar

√x + fourth root of x = 30

 

a) 11

b) 12

c) 13

d) 14

e) 15

Guest Dec 16, 2017
Sort: 

1+0 Answers

 #1
avatar+80910 
+2

x^(1/2)  +  x^(1/4)   = 30        subtract 30 from both sides

 

x^(1/2)   +  x^(1/4)  - 30    =  0     we can factor this directly as

 

[  x^(1/4 )  +  6  ]    [ x^(1/4)  - 5  ]   =  0

 

Settting both of these factors to 0  and solving for x, the first produces no solution

 

For the second, we have that

 

x^(1/4)  - 5  = 0     add 5 to both sides

 

x^(1/4)  = 5           take both sides to the 4th power

 

x  = 5^4   =    625

 

 

cool cool cool

CPhill  Dec 16, 2017

26 Online Users

avatar
avatar
We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.  See details