Question

help la ex 18 va rog :( urgent

Answer 1

a) 75+10√15+5-5√5×2√3=80+10√15-10√15=80
b) 6-2√18+3+8-9=8-6√2
c) 28√3+49-28√3+12=61
d) 147+14√3+1-28√6:2√2=148+14√3-14√3=148
e) 98-14√10+5+2√2×7√5=103-14√10+14√10=103
f) 54+24√6+16-20√6-√81=70+4√6-9=61+4√6

Answer 2

18. a) ( 5√3 + √5 )² - 5√5 × √12 
= 75 + 10√15 + 5 - 5√5 × 2√3 =
= 75 + 10√15 + 5 - 10√15 = 75 + 5 = 80

b) ( √6 - √3 )² + ( 2√2 -3 )( 2√2 + 3 ) =
= 6 - 2√18 + 3 + 4 × 2 - 9 =
= 6 - 6√2 + 3 + 8 - 9 = 8 - 6√2

c) 28√3 + ( 7 - 2√3 )² =
= 28√3 + 49 - 28√3 + 12 =  49 + 12 = 61 

d) ( 7√3 + 1 )² - 28√6 : √8 =
= 147 + 14√3 + 1 - 28√6/√8 =
= 147 + 14√3 + 1 - 28√3/√4 =
= 147 + 14√3 + 1 - 28√3/2 =
= 147 + 14√3 + 1 - 14√3 =  147 + 1 = 148 

e) ( 7√2 - √5 )² + √8 × √ 245 =
= 98 - 14√10 + 5 + √1960 =
= 98 - 14√10 + 5 + 14√10 = 98 + 5 = 103 

f) ( 3√6 + 4 )² - 20√6 - (√3)^4 =
= 54 + 24√6 + 16 - 20√6 - 3² =
= 54 + 24√6 + 16 - 20√6 - 9 = 
= 61 + 24√6 - 20√6 = 61 + 4√6