5у-13=38
5у=25
у=25:5
у=5
98-у=15
у=98-15
у=83
40+3=43
60+9=69
30+7=37
80+1=81
-0,8х-(0,6х-0,7y)=-0.8x-0.6x+0.7y=-1.4x+0.7y=0.7(2x-y)
<span>Если 2x-y=-8 ,то -0.8x-(-0.6x-0.7y)=0.7*(-8)=-5.6</span>
215 - CCXV
<span>140 - CXL </span>
<span>378 - CCCLXXVIII </span>
<span>294 - CCXCIV</span>