Help please guys !!!!!!!!!!

Question

Help please guys !!!!!!!!!!

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Answer 1

Ответ:

9) последний3x-18-2x=18

x=18+18

x=36

x^2-x-6=0

D=(-1)^2-4×-6=25=5^2

x1=1-5/2=-4/2=-2

x2=1+5/2=6/2=3

10x+9=7x

10x-7x=-9

3x=-9

x=-3