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Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15

The perimeter of a rectangle is 42 inches. if the width of the rectangle is 6 inches, what is the length

Sam is a waiter at a local restaurant where he earns wages of $5 per hour sam figures that he also eams about $3 in tips for each person he serves sam works 6 hours on a particular day. if n represents the number of people sam serves that day, which of the following functions could sam use to figure ehis total earings for the do o a. en) = 30 o b. en) = 5n+ 18