1)-17,8-х-(у-100,4)=-17,8-х-у+100,4=82,6-х-у
2)-t+30,1-(-k+310 2/9)=-t+30,1+k-310 2/9=
-t+k+310 2/9+30 1/10=-t+k+310 20/90+30 9/90
=-t+k+340 29/90
-х-у-z+t+a+b
-x+a-b-y-c-d
S=Пr²=П (d/2)²=П×7²=49П
1) 120 см:12=10 см - длина рёбра
2) 10*10*10=1000 куб см - объём куба )))))))))))))))))
2520; 5*2
252; 2
126; 2
63; 3*3
7; 7
1
2520 = 2*2*2*3*3*5*7
(5/22 - 8/11) * 11/5 = 5/22 * 11/5 - 8/11 * 11/5= 1/2 - 8/5 = 0.5 - 1.6 = -1.1
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2y + 3x = 0
6(x-7) + 8y = 0
======
2y + 3x = 0
6x - 42 + 8y = 0
======
2y + 3x = 0
6x + 8y = 42 | / 2
=====
3x + 2y = 0
3x + 4y = 21
=====
y = -1.5x
3x + 4*(-1.5x) = 21
=====
3x + 4*(-1.5x) = 21
3x - 6x = 21
-3x = 21
x = -7
====
y = -1.5 * (-7) = 10.5
Ответ: (-7; 10,5)