9<span>х²-4=0
9</span>х²-2²=0
(3<span /><u />х-2)(3х+2)=0
3х-2=0 или 3х+2=0
х=2/3 х=-2/3
8(х-7)-3(2х+9)=15
8х-56-6х-27-15=0
2х=98
х=49
Ответ: х=49
Y=x²-10x+9
y=(x-5)²-25+9
y=(x-5)²-16
V(5,-16)
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c x: y=0, (x-5)²-16=0,(x-5)²-4²=0,(x-5+4)(x-5-4)=0,(x-1)(x-9)=0
a)x-1=0,x=1, X1(1,0)
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b)x-9=0, x=9, X2(9,0)
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c y: x=0, y=(0-5)²-16=(-5)²-16=25-16=9
Y(0,9)
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- 0,7х = - 0,56
0,7х = 0,56
х = 0,56 : 0,7
х = 0,8