How do I draw planes & make them intersect, contain noncollinear points & make plane containing point not on line l

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

Asmall business produces and sells balls. the fixed costs are $20 and each ball costs $4.32 to produce. each ball sells for $8.32. write the equations for the total cost, c, and the revenue, r, then use the graphing method to determine how many balls must be sold to break even.

Cody was 165cm tall on the first day of school this year, which was 10% taller than he was on the first day of school last year.