Every week he withdraws $35 from the $950 in his savings, and he wants at least $600 by the end of the summer. So we could write:
![\sf 950-35x\ge 600](https://tex.z-dn.net/?f=%5Csf%20950-35x%5Cge%20600)
Where 'x' is the number of weeks. Now let's solve it for 'x'.
Subtract 950 to both sides:
![\sf -35x\ge -350](https://tex.z-dn.net/?f=%5Csf%20-35x%5Cge%20-350)
Divide -35 to both sides, don't forget to switch the sign when dividing/multiplying by a negative number:
![\sf x\le 10](https://tex.z-dn.net/?f=%5Csf%20x%5Cle%2010)
So he can only withdraw at money for at most 10 weeks if he wants at least $600 left in his account.
Take 408/4 because there are 4 faces so that equals 102 m2