<span> 88880:110+x=809</span>
<span>808+х=809</span>
<span>х=809-808</span>
<span>х=1</span>
<span>
</span>
<span><span> k+12705:121=105</span></span>
<span><span>к+105=105</span></span>
<span><span>к=105-105</span></span>
<span><span>к=0</span></span>