Answer:
The operations done first are:
a) 42 (17 – 15) / (3 + 1) – 5 ; (17 -15) or (3 + 1) (parenthesis) are done first
b) 42 (17 – 15) / (3 + 1) – 5 ; 7 × 2 (multiplication) is done first
Step-by-step explanation:
from the mnemonic PEDMAS, the order of operations are: Parentheses, Exponents, Multiplication/Division, Addition/Subtraction.
hence in the first expression : 42 (17 – 15) / (3 + 1) – 5, the parenthesis (bracket is simplified first as follows:
(17 - 15) = (2) ; and (3 + 1) = (4) ; hence the expression will be simplified as follows: 42 (2) / (4) - 5.
Next, since there is no exponent in the expression, Multiplication follows:
42 (2) = 42 × 2 = 84 ; hence he expression becomes: 84 / 4 - 5
Next division follows : 84/4 = 21, therefore the expression becomes
21 - 5.
Finally, subtraction follows : 21 - 5 = 16
b) 5 + 7 x 2 - 9;
first, multiplication is done: 7 × 2 = 14, hence the expression becomes :
5 + 14 - 9.
Next in the order is addition : 5 + 14 = 19, hence, the expression becomes:
19 - 9.
Finally, subtraction follows: 19 - 9 = 10
