Answer:
14) answer is 4
15) proved
Step-by-step explanation:
x=7-4√3 , √x +1/√x
√(7-4√3) +1/√7-4√3)=
8-4√x/√(7-4√3)= 4 ( use calculator)
(81/16)^-3/4*[(25/9)^-3/2 ÷(5/2)^-3]=
(81/16)^-3/4= (9²/4²)^-3/4=(4^6/4)/(9^6/4)=8/(27)=8/27
(25/9)^-3/2= (9^(3/2))/(25^3/2)=27/125
(5/2)^-3=2³/5³ =8/125
put the number to find the result:
8/27[(27/125)÷(8/125)=
8/27[(27/125)×125/8)]= 125 in nominator and dinaminotor=1
8/27[27/8]=1 proved
