Question

Kiara tried to evaluate an expression. Here is her work:

9.2 + [63–50÷(54 5)]
= 9.2 + [63–50÷(20 5)] Step 1
= 9.2 + [63–50÷25] Step 2
= 9.2 + [63–2] Step 3
= 9.2 + 61 Step 4
= 18 + 61 Step 5
= 79 Step 6
Is Kiara's work correct?

Answer 1

Kiara's work was incorrect due to a mistake in the initial steps involving parentheses. The correct answer, when we follow the order of operations and rounding to the nearest tenth as per significant figures, is approximately 71.4.

Step-by-step explanation:

No, Kiara's work is not correct. Let's go through the steps to show where the mistake occurred and how to properly evaluate the expression.

Correction of Kiara's Work

1. First, address the operations inside the parentheses: (54 + 5). This is equal to 59, not 20, which was Kiara's mistake.
2. Next, perform the division within the brackets: 50 ÷ 59.
3. Subtract the result of the division from 63.
4. Finally, add the result to 9.2.

Let's perform these steps correctly:

1. Original Expression: 9.2 + [63 – 50÷(54 + 5)]
2. Step 1: Calculate inside the parentheses: 54 + 5 = 59
3. Step 2: Perform the division: 50 ÷ 59
4. Step 3: Subtract from 63: 63 – (50 ÷ 59)
5. Step 4: Add to 9.2: 9.2 + [63 – (50 ÷ 59)]

Correct Answer

To find the correct answer, we'll need a calculator:

1. 50 ÷ 59 is approximately 0.8475
2. 63 - 0.8475 is approximately 62.1525
3. Finally, 9.2 + 62.1525 equals approximately 71.3525

The correct answer is approximately 71.4 if rounded to the nearest tenth, as significant figures suggest.