Replace each question mark with one of the four mathematical signs: +, -, x, or /(divide). Each sign can be used only once.
7?5?4?7?6=15
P.S. YOU HAVE TO USE THE ORDER OF OPERATIONS
[(7+5)/4]x7-6
Mrs. B is correct and also added parentheses and brackets, which are necessary to clarify the order of operations. The problem should have made that clear.
To solve the equation 7?5?4?7?6=15 using the order of operations, we need to determine which mathematical signs to use in place of the question marks.
Let's break down the equation step by step:
Step 1: Division (/)
Since division is the first operation in the order of operations, let's start by finding the possible divisions. Looking for a pair of numbers that can be divided to get a whole number result:
7 divided by 5 equals 1.4
5 divided by 4 equals 1.25
4 divided by 7 equals 0.5714
7 divided by 6 equals 1.1667
Since none of these divisions result in a whole number, we can eliminate division as an option for the question marks.
Step 2: Multiplication (x)
Moving onto multiplication, let's find the possible multiplications. We have the remaining numbers:
7 x 5 = 35
5 x 4 = 20
4 x 7 = 28
7 x 6 = 42
None of these multiplications will give us the desired result of 15. Therefore, we can eliminate multiplication as an option as well.
Step 3: Addition (+)
Next, let's consider addition. We have the following sums:
7 + 5 + 4 + 7 + 6 = 29
7 + 5 + 4 + 7 - 6 = 17
7 + 5 + 4 - 7 + 6 = 15
7 + 5 - 4 + 7 + 6 = 21
7 - 5 + 4 + 7 + 6 = 19
Out of these, we find that 7 + 5 + 4 - 7 + 6 equals 15.
Therefore, we can substitute "+" for the first and fourth question marks to solve the equation:
7 + 5 + 4 + 7 - 6 = 15
So, the equation becomes:
7 + 5 + 4 + 7 - 6 = 15