<span>1)</span>3а+8а=1,87
<span>11а=1,87 </span>
<span>а=1,87/11 </span>
<span>а=0,17</span>
2)<span>7 z - 3z = 5,12 </span>
<span>z * (7 - 3) = 5,12 </span>
<span>4z = 5,12 </span>
<span>z = 5,12 / 4 </span>
<span>z= 1,28</span>
3)<span>2t + 5t + 3,18 = 25,3 </span>
<span>2t + 5t = 25,3 - 3,18 </span>
<span>t(2+5) = 22,12 </span>
<span>7t = 22,12 </span>
<span>t = 22,12 / 7 = 3,16</span>