0.7x=-2;
X=-2:0.7;
X=-2 6/7
A) x = -4.08 / 3
x = <span>-1.36
в) x = -0.45 /-5
x = </span><span>0.09</span>
82x=8054-672;
82x=7382;
x=7382/82;
<span> 7*(3х+8)+13*(6+5х)+2*(6х-13)=206
21х +56+78+65х+12х - 26=206
98х + 108=206
98х=206 - 108
98х=98
х = 98 : 98
х=1</span>