1). x+y=0
3x-y=4
x=-y
3x-y=4
3×(-y)-y=4
-3y-y=4
-y=4
y=-4
x=4 Ответ:x=4 y=-4
2) 2x+3y=6
3x-y=9
2x+3y=6
y=-9+3x
2x+3×(-9+3x)=6
2x-27+9x=6
11x=33
x=3
y=-9+3×3
y=0 Ответ x=3 y=0
x^2-2x+2=<span> x^2-2x+1-1+2=(x-1)</span>²+1
min=1 (x=1)
F'(x)=2cos2x-2cosx·sinx-1/x+2^x·ln2.