Question

If x=1/3-root8


find the value of xcube -2x square- 7x+5.​

Answer 1

Step-by-step explanation:

Hi

upadhyay

I am Rajiv pandey

solution of your question is here

x= 1/(3- √8)= 3+2√2 rationalizing

=> x³-2x²-7x+5

= (3+2√2)³-2(3+2√2)²-7(3+2√2)+5

= (17+12√2)(3+2√2) - ( 34+24√2)-(21+14√2)+5

= (99+70√2-34-24√2-21-14√2+5)

= ( 49+32√2)

ANSWER