How do you solve #7- ( 3x + 29 )^(1/4) = 3#?

1 Answer
Nov 28, 2016

#x=75 2/3~~75.bar6#

Explanation:

#color(blue)(7-(3x+29)^(1/4)=3#

We need to isolate #x#

Subtract #7# both sides

#rarr7-(3x+29)^(1/4)-color(red)(7)=3-color(red)(7)#

#rarr-(3x+29)^(1/4)=-4#

Multiply both sides by #-1# to make the left side positive

#rarr-(3x+29)^(1/4)*color(red)((-1))=-4*color(red)((-1))#

#rarr(3x+29)^(1/4)=4#

We use the formula

#color(red)(x^(z/y)=root(y)(x^z)#

So,

#color(red)((3x+29)^(1/4)=root(4)(3x+29)^1=root(4)(3x+29)#

#rarrroot(4)(3x+29)=4#

To get rid of the root sign,raise both sides to the power of #4#

#rarr(root(4)(3x+29))^4=4^4#

#rarr3x+29=256#

Subtract #29# both sides

#rarr3x+29-color(red)(29)=256-color(red)(29)#

#rarr3x=227#

Divide both sides by #3#

#rarr(3x)/(color(red)(3))=227/(color(red)(3))#

#color(green)(rArrx=227/3=75 2/3#