Question

12x+31=23x-22(x-2)-1=5(x-2)-7иy+20=-yРешите уровнения

Answer 1

$1)12x+31=23x-2 \\ 12x-23x=-2-31 \\ -11x=-33 \\ x=3 \\ \\ 12*3+31=36+31=67 \\ 23*3-2=69-2=67 \\ 67=67$
$2) 2(x-2)-1=5(x-2)-7 \\ 2x-4-1=5x-10-7 \\ 2x-5x=-10-7+4+1 \\ -3x=-12\\x=4 \\ \\ 2*(4-2)-1=2*2-1=4-1=3 \\ 5(4-2)-7=5*2-7=10-7=3 \\ 3=3$
$3)y+20=-y \\ y+y=-20 \\ 2y=-20 \\ y=-20/2 \\ y=-10$

Answer 2

12х+31=23х-2
12х-23х= -2-31
-11х= -33
х=3

2(х-2)-1=5(х-2)-7
2(х-2)-5(х-2)= -7+1
-3(х-2)= -6
х-2=-6: (-3)
х-2= 2
х=4

у+20= -у
у+у= -20
2у= -20
у= -10