2-1 1/15= 14/15
14/15 : 4/9 = 126/135 : 60/135 = 2,1
2 4/15 - 2,1 = 2 40/150 - 2 10/150 = 30/150 =1/5
1/5 + 2/3 = 3/15 + 10/15 = 13/15
<span>- 9 - 5 * (2 + 3 х) =</span> - 9 - 10 - 15 х = - 19 - 15 х
Упрощенное выражение : - 19 - 15 х
1)(а-b)*2 = 2a-2b
<span>2)(а+b)^2 =36
2a+2b=36
2a=36-2b
a=18-b
3) </span><span>а^2 -b^2=24
2a-2b=24
2a=24+2b
a=12+b</span>