algebra, 11/8

a-c block:   finish the following problems that were started in class:
                   1) b2.7b for B+C block (b2.7a for A-block), #1-10
                   2) b87, # 4-15
                   3) b88, # 20-24, 26
                   4) b89, # 30-32, 38-40

d-block:   finish the following problems that were started in class:
                all problems on  b132, b133, b134, b135, b136, b137, b138, b139