Решение: 5(2-х)-х+4<span>≤-4
10-5х-х+4</span><span>≤-4
6х</span><span>≤-4-4-10
6х</span><span>≤-18/:6
х</span><span>≤-3</span>
3 1/8-1 1/8=25/8-7/4= 28/8-14/8= 9/8=1 1/8
(a+b+c+d)²=a^2+b^2+c^2+d^2+2(ab+cd)+a(c+d)+b(c+d)=a^2+b^2+c^2+d^2+2(ab+cd)+(a+b)(c+d)
5/9x - 2/3x=20-11,
-1/9x=9,
x= 9:(-1/9),
x=-81.
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