If 2x-1=13, evaluate the expression -x^2-4x.

-77

Step-by-step explanation:

2x-1=13

2x=13+1=14

x=14/2=7

- 77

Step-by-step explanation:

The given expression is -x^2-4x; there is another expression (2x - 1 = 13), which can be solved for x as follows:

2x - 1 = 13  

Adding 1 to both sides, we get:  

2x = 14

Dividing both sides by 2 results in:  x = 7

Substituting 7 for x in   -x^2-4x   yields   -(7)^2-4(7), or:

-49 - 28, or -77

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step-by-step explanation:

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