Question 253296
Here is the original question:
(i) {{{x^(2/7)-3x^(1/7)-10=0}}}
Let U = x^(1/7). Doing this helps us to rewrite (i) as
(ii) {{{U^2-3U-10=0}}}.
Now factor (ii) to get
(iii) {{{(U-5)*(U+2)=0}}}
and solve for U to get
{{{U = 5}}} and {{{U= -2}}}
Now resub x^(1/7 back into U to get the values of x
x^(1/7) = 5 - - > x = 5^7
x^(1/7) = -2 - - > x = (-2)^7.