-15(15+x)-12(12x+1)+10=16(3x-16)-17(x+17)
-225 - 15x - 144x - 12 + 10 = 48x - 256 - 17x - 289
-159x - 227 = 31x - 545
31x + 159x = 545 - 227
190x = 318
x = 318 : 190
x = 1 64/95
4×16×25=(4×25)×16=100×16=1600
16/21х - 3/7х = 2.48 - 1.18
(16-9)/21х = 1.3
1/3х = 1.3
1.3*3х = 1
х = 1/3.9
х = 10/39