1) 5y-72=48-3y
5y+3y=48+72
8y=120
y=15
2) 53*(x-961)=3975
53*(x-961):53=3975/53
x-961=75
x=75+961
x=1036
3) (k+2958):87=134
k+2958 дробь 87=134
87*k+2958 дробь 87= 87*134
k+2958=11658
k=11658-2958
k=8700
4) 69+4m=2m+153
69+4m-2m=153
4m-2m=153-69
2m=84
m=42