<span>93*x=6231
x=</span><span>6231/93
x=67
93*67=6231
</span><span>15768:y=36
</span>y=15768/36<span>
y=438
</span><span>15768:438=36
</span><span>z:407=814
z=</span><span>814*407
z=331298
</span><span>331298:407=814</span><span>
</span>
<span>
</span>
3\5х*(-15)+0.8*(5-2х)
-х/3*3+4-1.6х
-х/9+4-5х/х
-45+20х-8х²/5х