so 10.
first parenthasees ()
so 10(2.1q-2)=21q-10
then you do the rest
21q-20+7.5+18
add like terms
28.5q-2
second
(-6y-2)+5(3+2.5y)
distribute the 5
15+12.5y
add like terms
-6y-2+15+12.5y
6.5y+13
3rd
1/2(6x+10)+1/3(6+9x)
distribute
3x+5+2+3x
add like terms
6x+7
4th
(3x+8)-6(2.5x-3)
distrubute
-15x+18
add like terms
3x+8-15x+18
-12x+26
5th
(7-3t)-5(-1.6t+5)
distribute
+8t-25
add like terms
7-3t+8t-25
5t-18
6th
1/2(12w+8)-1/5(10w-5)
distribute
6w+4-2w+1
add like terms
4w+5
