<span> а) х+11,5=10,5</span>
<span>х=10.5-11.5</span>
<span>х=-1</span>
<span><span>б)5+3х=8</span></span>
<span><span>3х=8-5</span></span>
<span><span>3х=3</span></span>
<span><span>х=1</span></span>
<span><span><span> в)6х-7-2х=3</span></span></span>
<span><span><span>4х=3+7</span></span></span>
<span><span><span>4х=10</span></span></span>
х=2.5
<span> г)0,6(х+7)=0,5(х-3)+6,9</span>
<span>0.6х+4.2=0.5х-1.5+6.9</span>
<span>0.6х-0.5х=-1.5+6.9-4.2</span>
<span>0.1х=4.2</span>
<span>х=42</span>