1) (c-7)(4+2c)-6c(1-3c)-(9c-2)+(3-c)
4c+2c²-28-14c-6c+18c²-9c+2+3-c
-26c+20c²-23
20c²-26c-23
2) 5(a+3)(5-a)-(a-8)(1-a)-2a(3a-6)
5(5a-a²+15-3a)-(a-a²-8+8a)-6a²+12a
25a-5a²+75-15a-a+a²+8-8a-6a²+12a
13a-10a²+83
-10a²+13a+83
3) 4(2a+1)(5a-3)-3(a+2)(a+3)
4(10a²-6a+5a-3)-3(a²+3a+2a+6)
40a²-24a+20a-12-3a²-9a-6a-18
37a²-19a-30
4)-2(6-3m)(m+1)+5(m-4)(m-5)
-2(6m+6-3m²-3m)+5(m²-5m-4m+20)
-12m-12+6m²+6m+5m²-25m-20m+100
-51m+88+11m²
11m²-51m+88