<span>у=х-1
у=-х+3
x-1=-x+3
x+x=3+1
2x=4
x=2
y=2-1
y=1
(x,y)=(2,1)</span>
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2х(х-4)(х+5)=0
2х=0
х1=0
х-4=0
х2=4
х+5=0
х3=-5
х^2-25=0
х^2=25
х=+-!/25
х1=-5
х2=5
х^2-8х+16=0
Д=64-4×1×16=0
х=8/2=4
<span>2 (х + 1) = 3 (х + 1)
2х + 2 = 3х + 3
х = - 1</span>