You would have to find the proportionality of the two. If his shadow is 3 feet long, and the tree's shadow is 9 that means it is proportioned by 3. So the height of the tree would be 15.
X=number of pounds
y=cost of pound .
x+y=cost
563+8=571 burgers to start with
He is false the equation should be as follows
ANSWER: y=7x-5 i put it in a graphing calculator