If f(x)=.5x+15 , what is the value of f(-4)

Fatima plans to spend at least $15 and at most $20 dollars on sketch pads and pencils. if she buys 2 sketchpads, how many pemcils can she buy while staying in her price range? fatima can buy between and pencils. ? (type whole numbers. use ascending? order.)

Me because i don't understand how to do it.: )

Which equation can be used to find the area of the parallelogram? a. = (6)(4)b. = (10)(4)c. = (10)(6)d. = 10(4+6)explain how to do it