<span>1) 3b+28/25=4;
75b+28=100
75b=100-28
75b=72
b=72/75
2)3a/4=15;
3a=4*15
3a=60
a=60/3
a=20
3)16a-24/6=12;
16a=12+4
16a=16
a=1
4)29b+172/3=5</span>³
29b=125-172/3
29b=375/3
29b=125
b=125/3
b=41 2/3
1×4=4 2×4=8 3×4=12 4×4=16 5×4=20
№№№№№№№№№№№№№№№№№№№№№№№№№№№№
CosA=корень1-(корень21/5)^2=2/5
cosA=sinB=2/5=0.4