Solve the Parenthesis Conundrum for -36: Tips and Tricks

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SUMMARY

The discussion focuses on solving the mathematical expression 2 ⋅ 8 ÷ 4 - 20 to equal -36 by correctly placing parentheses. The successful solution presented is 2 ⋅ [ ( 8 ÷ 4 ) - 20 ], which simplifies to 2 ⋅ -18, resulting in -36. The initial attempts failed to achieve the desired outcome due to incorrect placement of parentheses. The final solution highlights the importance of proper grouping in mathematical expressions.

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tionis
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Hi guys. I'm asked to insert parentheses where needed so that the following expression evaluates to the given number negative 36:

2 ⋅ 8 ÷ 4 - 20 = - 36

My attempts:

( 2 ⋅ 8 ) ÷ ( 4 - 20 ) = 16 ÷ -16 = -1

2 ⋅ ( 8 ÷ 4 ) - 20 = 2 ( 2 ) - 20 = -16

( 2 ⋅ 8 ÷ 4 ) - 20 = -16

I just don't know what other combination I can try that will yield -36 as a solution. Please help me. Thanks.
 
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Hint: 2 x -18 = -36

If you'll forgive the lack of parenthesis!
 
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PeroK said:
Hint: 2 x -18 = -36

If you'll forgive the lack of parenthesis!

I got it lol.

2 ⋅ [ ( 8 ÷ 4 ) - 20 ] = 2 [ ( 2 ) - 20 ]
= 2 [ -18] = -36

Thank you so much, PeroK! You're AWESOME!
 
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