128*14+х=2601
1792+х=2601
х=2601-1792
х= 809
проверка
128*14+809=2601
1792+809=2601
2601=2601
==========================
y-185*23 =500
y- 4255=500
y=4255+500
y=4755
проверка
4755-185*23=500
4755-4255=500
500=500
1)а+(-27)+48= a - 27 + 48 = a + 21
2)(1/4)²+(-5 3/7)+(-0,0625)= 1/16 - 5 3/7 - 1/16 = -5 3/7
============================
1) (2/3)² = 4/9
2) 6,375 = 6 3/8
3) 4/9 - 6 3/8 + 6 3/8 = 4/9
ответ: 4/9