Solve by substitution
-4x+y=6
-5x-y=21

One side of a rectangle is 7 feet shorter than seven times the other side. find the length of the shorter side if we also know that the perimeter of the rectangle is 306 feet.

Jenisey has $24 to spend on seven pencils. after buying them she had $10. how much did each pencil cost.?

Afamily has five members. a mom, a dad, two sisters, & a brother. the family lines up single file. what is the probabillity that the mom is at the front of the line