(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!

What is the equation in slope-intercept form of the linear function represented by the table? y -18 -1 -8 4 2 912 o y=-2x-6 o y=-2x+6 o y=2x-6 o y = 2x+6

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.

Awoman has 14 different shirts: 10 white shirts and 4 red shirts. if she randomly chooses 2 shirts to take with her on vacation, then what is the probability that she will choose two white shirts? show your answer in fraction and percent, round to the nearest whole percent.