(No links and no copying websites((Especially web 2.0 calc)) or you'll be reported If $a, b,c$ are positive integers less than $13$ such that\begin{align*}
2ab+bc+ca&\equiv 0\pmod{13}\\
ab+2bc+ca&\equiv 2abc\pmod{13}\\
ab+bc+2ca&\equiv 8abc\pmod {13}
\end{align*}then determine the remainder when $a+b+c$ is divided by $13$.
Thanks!

you forgot an image

step-by-step explanation:

in 2010, the population of the state of california is 37.29 × 10⁶

step-by-step explanation:

population of los angeles = 3.79 × 10⁶

population of california = 9.84 × population of los angeles

                                        = 9.84 × 3.79 × 10⁶

                                        = 37.2936 × 10⁶

                                        = 37.29 × 10⁶

∴ in 2010, the population of the state of california is 37.29 × 10⁶

hello there!

i believe the answer is

(cot2+1)/sec2=cot2

    csc2/sec2=cot2

  (1/sin2)/(1/cos2)=cot2

  (1/sin2)(cos2/1)=cot2

  cos2/sin2=cot2

  (1/tan2)=cot2

  (cot2)=(cot2)

hope this !

hyperz ^_^