А)-7b2(3b+2)
б)(m-n)(n+3)
в)(9a-b)(9a+b)
г)3y2(y-6)^2
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а)(3a-2b)(3a+2b)
б)(6c-5)^2
в)(5-6c)^2
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(x+2)^2-49=0
x2+4x+4-49=0
x2+4x-45=0
x(x+4)=45
x=45 или x+4=45
x=41
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тождество
x2+14x-51=(x+17)(x-3)
x2+14x-51=x2-3x+17x-51
x2+14x-51=x2+14x-51