18. Write an equation in point-slope form of the line that passes through the given point and with the given slope m. (-3,1);m=3

20. Write an equation in slope-intercept form of the line that passes through the given point and is parallel to the graph of the given equation.
(-3,-5);y=-2x+2

21. Write an equation in slope-intercept form of the line that passes through the given point and is perpendicular to the graph of the given equation.
(0,0);y=-3x+2

Solve for x and y: 217x + 131y = 913; 131x + 217y = 827

Ihonestly have no clue if it's each or none.

Each of the following data sets has a mean of x = 10. (i) 8 9 10 11 12 (ii) 7 9 10 11 13 (iii) 7 8 10 12 13 (a) without doing any computations, order the data sets according to increasing value of standard deviations. (i), (iii), (ii) (ii), (i), (iii) (iii), (i), (ii) (iii), (ii), (i) (i), (ii), (iii) (ii), (iii), (i) (b) why do you expect the difference in standard deviations between data sets (i) and (ii) to be greater than the difference in standard deviations between data sets (ii) and (iii)? hint: consider how much the data in the respective sets differ from the mean. the data change between data sets (i) and (ii) increased the squared difference îł(x - x)2 by more than data sets (ii) and (iii). the data change between data sets (ii) and (iii) increased the squared difference îł(x - x)2 by more than data sets (i) and (ii). the data change between data sets (i) and (ii) decreased the squared difference îł(x - x)2 by more than data sets (ii) and (iii). none of the above