1 х>0
2 x не равен -5, х>0
<span>15-3(2х-4)=11-х</span>
15-6x+12=11-x
-6x+x=11-12-15
5x=-16
x=16:5
x=-3.2
49y²-64=0
(7y-8)(7y+8)=0
x1= 8/7, x2= -8/7