f(1\2a+2)= 6(1\2a+2)^2=6(1\4a^2+2a=4)=1,5a^2+12a+24;
7xквадрат-12=0
x(7x-12)=0
x=0 или 7x-12=0
7x=12
x= 12/7
x=1целая 5/7
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