chetan2u wrote:
The equation \(6 × 5 – 4 ÷ 2 – 3 + 7)^0– 1)^2 = 6\) is missing two opening parentheses. It can be made true if opening parentheses are placed immediately before each of two of the numbers.
Assume that standard order-of-operations principles are followed, whereby multiplication and division are performed before addition and subtraction, unless parentheses indicate otherwise. Select in the table a number before which the first opening parenthesis could be placed and a number before which the second opening parenthesis could be placed, such that the equation would express a true statement. Make only two selections, one in each column.
\(6×5–4÷2–3+7)^0–1)^2=6\)
We can PLUG IN THE ANSWERS.
If opening parentheses are placed before 6, we get:
\((6×5–4÷2–3+7)^0–1)^2=6\)
Taking the square root of both sides, we get:
\(6×5–4÷2–3+7)^0–1=\sqrt{6}\)
Not viable.
If opening parentheses are placed before 5, we get:
\(6×(5–4÷2–3+7)^0–1)^2=6\)
Dividing both sides by 6, we get:
\((5–4÷2–3+7)^0–1)^2=1\)
Taking the square root of both sides, we get:
\(5–4÷2–3+7)^0–1=1\)
\(5–4÷2–3+7)^0=2\)
This seems viable.
Testing the remaining answer choices:
Before 4 --> \(5–(4÷2–3+7)^0=2\) --> 5-1=2 --> Nope
Before 2 --> \(5-4÷(2–3+7)^0=2\) --> 5-4=2 --> Nope
Before 3 --> \(5–4÷2–(3+7)^0=2\) --> 5-2-1 = 2 --> Success!