Which expression is modeled by this arrangement of tiles?
40 divided by (negative 10)
40 divided by 10
40 divided by 40
40 divided by 40

it should be 40 divided by 4

Explanation:

the tiles arrange into 10 2x2s, so 10 groups of 4

not 4 groups of 10 if it were divided by 10

the causes of the dust bowls were severe droughts,   lands became dry and hard, temperature was higher than usual, hot and dry conditions killed crops, high winds. because of those factors, the winds kicked up dry soil and created clouds of dust.