Question

(9y+1)⋅(7y−4)=(63y−5)(y+1) Решите уравнение

Answer 1

(9y+1)⋅(7y−4)=(63y−5)(y+1)
63у²+7у-36у-4=63у²+63у-5у-5
63у²+7у-36у-63у²-63у+5у=4-5
-87у=-1
у=$\frac{1}{87}$

Answer 2

63y-36+7y-4=63y^{2}+63y-5y-5=0
63y^{2}+63y-5y-5-63y+36-7y+4=0
(+63y) и (-63y) сокращаем
63y^{2}-5y-5+36-7y+4=0
63y^{2}-12y+35=0
1) D=в^{2}-4ac= (-12)^{2} - 4*63*35= 144-8820
2)$x_{1.2}= \frac{-B}{2a}= \frac{12}{2*63}= \frac{12}{126}= 0.09$