Решите уравнениеy + 4 = 2y - 5,7(y - 3 ) = -2(y + 3).

Question

Решите уравнение

y + 4 = 2y - 5,

7(y - 3 ) = -2(y + 3).

Answer 1

2Y - Y = 4 + 5 
Y = 9
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7Y - 21 = - 2Y - 6 
7Y + 2Y = - 6 + 21 
9Y = 15 
Y = 1 ( 6/9  ) = 1 ( 2/3 )

Answer 2

y + 4 = 2y - 5
y-2y+4=-5
-y+4=-5
-y=-5-4
-y=-9
y=9


7(y - 3 ) = -2(y + 3)
7y-21=-2y-6
7y+2y-21=-6
9y-21=-6
9y=21-6
9y=15
y=15/9
y=5/3
y= 1 2/3