6.1 ANSWERS in-depth path
Exercise 1
Calculate
a) 42 + 3 - 1
= 16 + 3 - 1
= 19 -1
= 18
b) 62 - 32
= 36 - 9
= 27
c) (7 - 6)2
= (1)2
= 1
d) (1/4)2 + (2/3)2
= 1/16 + 4/9
= 9/144 + 64/144
= 73/144
e) 7 - 62 : 3
= 7 - 36 : 3
= 7 - 12
= -5
f) √49 + 42 - 1
= 7 + 42 - 1
= 7 + 16 - 1
= 22
g) 3 . √121 + 7 . √625
= 3 . 11 + 7 . 25
= 33 + 175
= 208
Exercise 2:
Calculate
a) (-8)2
= -8 . -8
=64
b) √81
= 9
(because 9 . 9 = 81)
c) √49 + 42 - 1
= 7 + 42 - 1
= 7 + 16 - 1
= 22
d) 3 . √121 + 7 . √625
= 3 . 11 + 7 . 25
= 33 + 175
= 208
Exercise 3
Calculate
a)√-7
= √( 7 . -1 )
= √( 7 . i 2 )
= √7 . √i 2
= √7 . i
= i√7
b) √( 9 - 10 )
= √-1
= √i 2
= i
c) 3√-13 + 5 . 4 2
= 3 . √( 13 . -1 ) + 5 . 16
= 3 . √13 . √i 2 + 5 . 16
= 3√13 . i + 5 . 16
= 3i√13 + 5 . 16
= 3i√13 + 80