Ответ:
1. ( x - 7 ) ( x + 3 ) = 0
x - 7 = 0
x + 3 = 0
x1= 7
x2= - 3
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( 7 - 7 ) ( -3 + 3 ) = 0
0 = 0
2. ( 4x + 3 ) ( 2x + 1) = 0
4x + 3 = 0
2x + 1 = 0
x1= 3/4 или 0,75
x2= - 1/2 или - 0,5
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( 4 * 3/4 + 3 ) ( 2 * 1/2 + 1) = 0
0 = 0