The limit as x approaches negative infinity is...? I know the correct answer is B. Can someone work it out for me so I can understand?

Tabby sells clothing at a retail store, and she earns a commission of 6.25% on all items she sells. last week she sold a pair of jeans for $32.50, a skirt for $18.95, and 2 blouses for $14.95 each. what was tabby's total commission? a $4.15 b $5.08 c $81.35 d $348.60

What is the value of x in the equation7x+2y=48 when y=3

Can someone me with this? i’m not sure what to put for my equations.