Solve the following equations:


Operating R1→R1+R2+R3



Taking (x+9) common from R1



Operating C1→C1-C3, C2→C2-C3



Expanding with R1


0=(x+9)(0-(x-2)(7-x))


0=(x+9)(7-x)(2-x)


Either x+9=0 or 7-x=0 or 2-x=0


∴ x=-9 or x=7 or x=2


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