Question

If x =
1 upon 2−√3 find the value of x^3 – 2x^2 – 7x + 5

Answer 1

Answer:

x=1/2-√3

rationalise

x=2+√3

Step-by-step explanation:

put the vale of x in x³– 2x² – 7x + 5

(2+√3)³-2(2+√3)²-7(2+√3)+5

8+9√3+12√3+18-2(4+3+4√3)-14-7√3+5

26+21√3-14-8√3-9-7√3

3+6√3