7х = 4х^2
5х^2 - 3 = 0

1) 7x = 4x^2
7x-4x^2=0
x(7-4x)=0
x=0;
7-4x=0
4x=7
x=7/4

2) 5x^2-3=0
5x^2=3
x^2=3/5
x=V3/5 ( V - koren')

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