Đáp án: + Giải thích các bước giải:
$1$.
$a$) $2 370 - 179 +21= 2191 + 21= 2212$.
$b$) $100 : 5 .4 = 20 . 4 = 80$.
$c$) $396 : 18 : 2 = 22 : 2 = 11$.
$2$.
$a$) $143 - 12.5 = 143 - 60 = 83$.
$b$) $27.8 - 6:3 = 216 - 2 = 214$.
$c$) $36 - 12:4 .3 + 17 = 36 - 9 + 17 = 44$.
$3$.
$a$) $3^2. 5^3 + 9^2 = 9.125 + 9.9 = 9(125+9) = 9.134 = 1306$.
$b$) $8^3 : 4^2 - 5^2 = 512 : 16 - 25 = 7$.
$c$) $3^3 . 9^2 - 5^2 . 9 + 18:6 = 9(27.9 - 25) + 3 = 9. 218 + 3= 1965$.
$4$.
$a$) $32 - 6.(8 - 2^3) + 18 = 32 - 6.0 + 18 = 32 + 18 = 50$.
$b$) $(3.5 -9)^3 . ( 1+2.3)^2 + 4^2 = 6^3. 7^2 + 4^2 = 10600$.
$5$.
$a$) $9234 : [3.3.(1+8^3)]= 9234 : (9.513)= 9234 : 4617= 2$.
$b$) `76 - {2.[2.5^2 -(31-2.3)]} + 3.25`
`= 76 - [2.(50 - 25)] + 75`
`= 76 - 50 + 75`
`= 101`.
