(1)
0.8x+2=7.6
0.8x=7.6-2
0.8x=5.6
x=7
(2):x/45=0.28
x=0.28*45
x=12.6
(3):6.7x=2.041
x=2.041/6.7
x=0.3
(4):
960/x=12
x=960/12
x=80