Question

Oblicz :

a) 1+2x²+(x+9)²-2(x+7)(x-7)=(x-6)²

b) (2x-3)²-(1-x)(1+x)+x=(3x-1)²+(1-2x)(2x+1)-9

c) x-⅓)²-(x+2)(x-2)+8/9=(x+5)²-x²-2/3x

Answer 1

A) 1+2x²+x²+18x+81-2(x²-7x+7x-49)=x²-12x+36
1+2x²+x²+18x-2x²+98=x²-12x+36
2x²+x²+18x-2x²-x²+12x=36-98-1
30x=-63/30
x=-2.1
b)2x²-12x+9-(1-x²)+x=9x²-6x+1+2x+1-4x²-2x²-9
2x²-12x+9-1+x²+x=9x²-6x+1+2x+1-4x²-2x²-9
2x²-12x+x²+x-9x²+4x²+6x-2x+2x²=1+1-9-9+1
-7x=-15/(-7)
x=⁷/¹₅
c)x²-2/3x+1/9-x²+4+8/9=x²+10x+25-x²-2/3x
x²-2/3x-x²-x²-10x+x²+2/3x=25-1/9-4-8/9
-10x=20/(-10)
x=(-2)