We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website. cookie policy and privacy policy.
 
+0  
 
0
312
1
avatar

√x + fourth root of x = 30

 

a) 11

b) 12

c) 13

d) 14

e) 15

 Dec 16, 2017
 #1
avatar+99276 
+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

 Dec 16, 2017

24 Online Users

avatar
avatar
avatar