$ (20b + 80) is the cost to buy a frame for the panting given that measures b meters by 4 meters and charges $10 per meter for a wooden frame. This can be obtained by finding the perimeter of the painting and multiplying with the cost of wood per meter.
<h3>What is the cost of buying a frame for the painting?</h3>
Given that,
length of the painting (l) = b meters
width of the painting (b) = 4 meters
Perimeter of the painting = 2(l+b)
= 2(b+4)
= 2b + 8
Cost of the frame = (2b + 8)× $10 per meter
= $ (20b + 80)
Hence $ (20b + 80) is the cost to buy a frame for the panting given that measures b meters by 4 meters and charges $10 per meter for a wooden frame.
Learn more about finding cost of frame:
brainly.com/question/16757070
#SPJ4