X=-2y-6
y+3(-2y-6)=2
y-6y-18=2
-5y=20
y=20:(-5)
y=-4
x=-2×(-4)-6
x=8-6
x=2
Ответ:(2;-4)
0,49^ (-1/2) = (49/100)^(-1/2) = (100/49)^(1/2) = √100/49 = 10/7
X(x-3)≤0
x=0 x=3
+ _ +
----------[0]------------------[3]---------------------
x∈[0;3]
5*16-5*(-12)-7*4+(-21)=80+60-28-21=91