Question 702263
 {{{x}}} is a root of the quadratic equation {{{x^2=3-2x}}}, show that
a) {{{x^3=7x-6}}},
b) {{{x^4=21-20x}}}.
**
x^2=3-2x
x^2+2x-3=0
(x+3)(x-1)=0
x=-3
or
x=1
..
a) {{{x^3=7x-6}}},
For x=-3
-3^3=7*-3-6
-27=-21-6
-27=-27
..
for x=1
1^3=7*1-6
1=1
..
b) {{{x^4=21-20x}}}
for x=-3
(-3)^4=21-20(-3)
81=21+60
81=81
..
for x=1
1^4=21-20(1)
1=1