Afirst number plus twice a second number is 5.twice the first number plus the second totals 31.find

Mercury poisoning is dangerous overload of mercury within the body. a major source of mercury within the body, a major source of mercury poisoning is consuming fish that contain mercury. certain fish are more prone to having higher levels of mercury than others. the pie chart shows the distribution of four breeds of fish at a hatchery. the hatchery has approximately 6,000 fish. a biologist from the centers for disease control and prevention randomly test 5% of each breed of fish for mercury content. her findings are shown in the following table. based on the biologist's findings, if a single salmon is randomly selected from those that were tested, what is the probability that this particular fish would have a dangerous mercury level? a) 0.001 b) 0.004 c) 0.02 d) 0.08

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

Identify an equation in point slope form for the line perpendicular to y=3x+5 that passes through (4,-1)