Solve each system by the equation: 1.-x-5y=-19
y=-6x-2

2.3x+7y=24
y=6

3.-x-6y=-2
y=4x+17

4.-5x+y=-2
-4x+6y=-12

5.2x+y=8
4x-y=-8

6.-6x+4y=2
x+y=-7

He weights of 2-pound bags of best dog food are approximately normally distributed with a given mean  and standard deviation  according to the empirical rule, what percentage of the bags will have weights within 3 standard deviations of the mean? 47.5%68%95%99.7%