Need help asap! will give brainliest<3

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

Graph the line that represents a proportional relationship between d and t with the property that an increase of 33 units in t corresponds to an increase of 44 units in d. what is the unit rate of change of dd with respect to t? (that is, a change of 11 unit in t will correspond to a change of how many units in d? )

Pyramid shown has a square base that is 18 inches on each side has a surface area of 164 square inches what is the slant height