0.45:315=1:х
0.45х=315
х=700
315+700=1015
1) (409*231+55521):5000=(94479+55521):5000=150000:5000=30
2)(188804+11196)-876=200000-876=199124
3)(134550:414+1675)+8000):125+20=(325+1675)+8000):125+20=(2000+8000):125+20=10000:125+20=80+20=100
49....................................................................
5( x - 1,5 ) = 4 2/3x - 8 3/14
5x - 7,5 = 4 2/3x - 8 3/14
5x - 4 2/3x = 7,5 - 8 3/14
1/3x = 7 7/14 - 7 17/14
1/3x = - 5/7
x = - 5/7 : 1/3
x = - 15/7
x = - 2 1/7