Question

I’m stuck on this question, may someone help?

Use operation signs, -,x,+,/ once each to fill in the blanks so that the value of the expression is 5.


3 _ 2 _ (8 _ 7) _ 1 = 5

Answer 1

3 + 2 ÷ (8 - 7) × 1 = 5

Explanation:

There is likely more than one way to do this problem.

Here's one way:

3 + 2 ÷ (8 - 7) × 1 = 5

Do parenthesis first.

3 + 2 ÷ (1) × 1 = 5

Multiply or divide in order from left to right.

3 + 2 × 1 = 5

3 + 2 = 5

Lastly, add.

5 = 5

So, this checks out.

One possible answer is:

3 + 2 ÷ (8 - 7) × 1 = 5

Answer 2

3 + 2 × (8 - 7) ÷ 1

Explanation:

You want to fill in math operations to make the expression 3 _ 2 _ (8 _ 7) _ 1 equal to 5, using +, -, ×, and ÷ once each.

Analysis

It is unlikely that ÷ will go between 3 and 2, because that would give a fraction not easily modified to give a value of 5.

It is likely that + or - goes inside the parentheses, as there would be no need for parentheses if that operation were × or ÷. The minus sign seems more appropriate, since adding 8 and 7 would give 15, a value not easily modified to make 5.

Using - inside parentheses reduces the problem to ...

3 _ 2 _ 1 _ 1 = 5 . . . . . with available remaining operators: +, ×, ÷

It seems appropriate to make this be ...

3 + 2 = 5 . . . . . . uses the + operation in the first blank

which requires that 2 _ 1 _ 1 = 2 using × and ÷. We can only use them in that order if we want the value 2: 2 × 1 ÷ 1 = 2

The desired expression is ...

3 + 2 × (8 - 7) ÷ 1 = 5