Question

how to solve sigma qestions in physics

Answer 1

Remember that [math]\sum\limits_{k=a}^bC=C(1+b-a)[/math] when [math]C[/math] is not dependent on [math]k[/math].

[math]\sum\limits_{i=0}^3x=-4[/math]

[math]x(1+3-0)=-4[/math]

[math]4x=-4[/math]

[math]x=-1[/math]