1) а + (b)-(-2b) = a + b + 2b = a + 3b
2)-a - (+a) + 2b -(-b) = -a - a + 2b + b = -2a + 3b
24,6 + (-35,9) -(-6,5)+(-5,2)= 24.6 -35.9 + 6.5 - 5.2 = -10
(-32) -(13,8)-(+26,3)-(-27,5)= -32 - 13,8 -26,3 +27,5 = - 44,6
( 1 1/12 + 3,75) - (-Х) = 4,5
13/12 + 15/4 + х = 4,5
13/12 + 45/12 + х = 4,5
58/12 +х = 4,5
х = 4,5 - 29/6
х = 9/2 - 29/6
х = - 2/6 = - 1/3
Х - ( 7 5/9 - 5 1/6) = - 3,5
х - 68/9 + 31/6 = -3,5
х - 136/18 +93/18 = -3,5
х = -3,5 + 43/18
х = - 7/2 +43/18
х = - 63/18 +43/18
х = - 20/18 = - 10/9 = - 1 ц 1/9
- ( 5 2/3 - 1,6) - Х = 6 1/3
- 5 2/3 + 1,6 - х = 6 1/3
- 17/3 + 8/5 - х = 6 1/3
- 85/15 + 24/15 - х = 6 1/3
- 61 /15 - х = 19/3
- х = 19/3 + 61/15
- х = 95/15 +61/15
- х = 52/5
х = - 10 ц 2/5
Х-(- 4,6+ 3 4/7)= - 8 1/14
х +4,6 - 3 4/7 = - 8 1/14
х + 23/5 - 25/7 = - 113/14
х + 36/35 = - 113/14
х = - 113/14 -36/35
х = - 601 /35 = - 17ц 6/35