где ......................................................
3y+x=12, y-4x+9=0, K(x,y)=?
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x+3y=12
-4x+y=-9
----
x=12-3y
-4x+y=-9
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x=12-3y
-4(12-3y)+y=-9
---
x=12-3y
-48+12y+y=-9
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x=12-3y
13y=48-9
---
x=12-3y
13y=39
---
x=12-3y
y=3
---
x=12-3.3
y=3
---
x=12-9
y=3
---
x=3
y=3
----
K(3,3)
=======
2х² + 4х - 3 = 0
D = 16 - 4 * 2 * (-3) = 16 + 24 = 40
√D = √40
x1 = (-4 + √40)/4 =
x2 = (-4-√40)/4 =
Lg 0,0025 + lg 0,0004 = <span>lg (0,0025*0,0004) =lg 10^-6 = -6 lg 10 = -6 *1 = -6
^ степень</span>