<span>а)(х+3)-17=-20 </span>
<span>x+3-17=-20</span>
<span>x= -20+14</span>
<span>x=-6</span>
<span>
</span>
<span>б) -(10-В)+23,5=-40,4</span>
<span>-10 + b + 23.5=-40,4</span>
<span>b=-40,4 + 10 - 23.5</span>
b=-53,9
<span>
</span>
<span>в)(м+8/15)-2/15=0,8</span>
м+8/15-2/15=4/5
м=4/5-8/15+2/15
м=0,4