Răspuns:
a) 5^2 + 9^2 - 2^5 =
25 + 81 - 32 =
=74
b) 3 × 7^2 - 4^2 =
3 × 49 - 16 =
147 -16 =
= 131
c) 3 × 4^3 + 2 × 9^2 =
3 × 64 + 2 × 81 =
192 + 102 =
= 354
d) (3^3 - 6) : 21 =
( 27 - 6) : 21 =
21 : 21 =
= 1
e) (12^2 - 11^2) : 1^20 =
( 12 - 11) : ( 12 + 11) : 1 =
1 × 23 =
= 23
f) 5^1 × (13^2 + 4^3) =
5( 13^2 + 64) =
5 × 13^2 + 320 =
5 × 169 + 320 =
845 + 320 =
= 1165
g) (19^2 - 17^2) × (10^3 - 15^2) =
(19 - 17) × (19 + 17) × (10^3 - 15^2) =
( 2 × 36) × (10^3 - 15^2) =
72( 10^3 - 15^2) =
72 × 10^3 - 72 × 15^2 =
72 × (10^3 - 15^2) =
72 × 10^3 - 72 × 15^2 =
72 (10^3 - 15^2) =
72 (1000 - 225) =
72 × 775 =
= 55 800
h) 20^2 - 2 × 10^2 + 10 × 2^2 =
(10 × 2)^2 - 2 × 10^2 + 10 × 2^2 =
10^2 × 2^2 - 2 × 10^2 + 10 × 2^2 =
(10^2 - 2×5^2 + 10) × 2^2 =
(100 - 2 × 25 + 10) × 4 =
(100 - 50 + 10) × 4 =
60 × 4 =
= 240
i) 20^3 × (16^2 - 4^2) =
20^3 × (2^8 - 2^4) =
20^3 × (2^8 - 16) =
20^3 × 2^8 - 16 × 20^3 =
( 2^8 - 16) × 20^3 =
( 256 - 16) × 8000 =
240 × 8000 =
= 1.192.000
~< Cred ca la ultimul ex. este greșit cv..>~
~< Dar celelalte sunt corecte>~
~< Btw semnul asta "^" inseamna la putere>~
