Answer:
48f + 140 = 572
9 flowers
Step-by-step explanation:
Isabella gets a fixed payment of $140 per week and in addition to that, she gets $48 per flower that she delivers to the biologist.
In the last week, Isabella earned $572 from the biologist.
If she delivers f numbers of flowers to the biologist then the equation of Isabella's earning will be
48f + 140 = 572 ......... (1)
Now, solving this equation (1), we get 48f = 432, ⇒ f = 9
Therefore, she collected 9 flowers last week. (Answer)