1)
3(х-4)+2=5х-4
3х-12+2=5х-4
3х-5х=10-4
-2х=6
х = -3
2)
х²-5х=0
х(х-5)=0
х(1)=0; х(2)=5
3)
2х²-х-3 = 0
Д=1+24 = 25 = 5²
х(1) = (1+5)/4 = 6/4 = 3/2 = 1,5
х(2) = (1-5)/4 = -4/4 = -1
4)
х + х/3 = 1/6 | * 6
6x+2x=1
8x=1
x = 1/8
5)
(x-6)/2 + (x+7)/4 = 1 |*4
2(x-6) + (x+7)=4
2x-12+x+7 = 4
3x = 5+4
3x=9
x=3
6)
3x²-27 = 0 | :3
x² - 9 = 0
(x-3)(x+3)=0
x(1) = 3; x(2) = -3
№1 2х+3у=3 /*4
5х-4у=19 /*3
8х+12у=12
15х-12у=57
8х+12у+15х-12у=57+12
23х=69
х=3
2*3+3у=3
3у=-3
у=-1
№2
у=-4х+3
Объяснение:
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