Solve the operations inside the innermost parenthesis.
This business/management problem is solved step by step below, with detailed explanations to help you understand the method and arrive at the correct answer.
ScanSolve AI Answer
To find the value of the expression $[21 + 14 - 7 \times (91 \div 7 - 12) + 42]$, we follow the order of operations (BODMAS/PEMDAS): Brackets, Orders (powers/roots), Division and Multiplication (from left to right), Addition and Subtraction (from left to right).
Step 1: Solve the operations inside the innermost parenthesis.
First, perform the division:
$$91 \div 7 = 13$$
Next, perform the subtraction within the parenthesis:
$$13 - 12 = 1$$
So, the expression inside the parenthesis $(91 \div 7 - 12)$ simplifies to $1$.
Step 2: Substitute this value back into the main expression.
The expression becomes:
$$[21 + 14 - 7 \times 1 + 42]$$
Step 3: Perform the multiplication.
$$7 \times 1 = 7$$
The expression now is:
$$[21 + 14 - 7 + 42]$$
Step 4: Perform additions and subtractions from left to right.
First, add $21$ and $14$:
$$21 + 14 = 35$$
Next, subtract $7$ from $35$:
$$35 - 7 = 28$$
Finally, add $42$ to $28$:
$$28 + 42 = 70$$
Thus, the value of the expression is $70$.
Comparing this with the given options:
1. 80
2. 50
3. 70
4. 60
The calculated value matches option 3.
The final answer is $\boxed{\text{70}}$
