Respuesta :
Answer:
-77
Step-by-step explanation:
2x-1=13
2x=13+1=14
x=14/2=7
[tex]-x^2-4x=-(7)^2-4(7)=-49-28=-77[/tex]
Answer:
- 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