Запиши решение и ответ:-)

а) 2(2+у)=19-3у

4+2у=19-3у

2у+3у=19-4

5у=15/:3

у=3

б) <span>(4-c)+2(c-3)=-13</span>

<span>4-с+2с-6=-13</span>

<span>2с-с=-13-4+6</span>

<span>с=-11</span>

в)<span>-3(3b+1)-12=12</span>

<span>-9b-3-12=12</span>

<span>-9b=12+15</span>

<span>9b=-27/:9</span>

<span>b=-3</span>