Question

x²=12x
x²=-5x
13x²=169
x-6x=0

Answer 1

x=√12x
x=√-5x
13x=√169
-5x=0

Answer 2

x²=12x
x²-12x=0
x'=12
x"=0

x²=-5x
x²+5x=0
x'=0
x"=-5

13x²=169
13x²-169=0
x'=1
x"=-1

x-6x=0
5x=0
x'=10
x"=0