16÷4=4 длина 1 квадратика
S=1/2×4×4=8см
1) <span>x+y-3>z+5</span>
<span> х-3>z-y+5; y-z-3>5-x; x+y=z+8; x-8>z-y</span>
<span>2) <span> a+1-c<p-q-6</span></span>
<span><span> a) a-c-p+q<-6-1</span></span>
<span> a-c-p+q<-7</span>
<span> б) a+1+q+6<p+c</span>
<span> a+q+7<p+c</span>
4 га = 40000 кв м
5 га = 50000 кв м
12 а =12000 кв м
6 с = 6000 кв м
А13=а1+12d
a18=a1+17d
a1+12d+a1+17d=4.2
2*a1+29d=4.2
S30=(2*a1+29d)/2*30=4.2/2*30=2.1*30=63