Which pair of angles are supplementary angles

If f(x)=2x-6 and g(x)=3x+9, find (f-g)(x)

Luke started a weight-loss program. the first week, he lost x pounds. the second week, he lost pounds less than times the pounds he lost the first week. the third week, he lost 1 pound more than of the pounds he lost the first week. liam started a weight-loss program when luke did. the first week, he lost 1 pound less than times the pounds luke lost the first week. the second week, he lost 4 pounds less than times the pounds luke lost the first week. the third week, he lost pound more than times the pounds luke lost the first week.

Solve the system of equations using the substitution method. {y=−3x+7x=−2y−16 enter your answers in the boxes.