Question

Решите уравнение ! ! 30 4(х-3)=х+6 4-6(х+2)=3-5х (5х++14)=0 2,7+3y=9*(y-2,1)

Answer 1

$4(x-3)=x+6\\ 4x-12=x+6\\ 4x-x=6+12\\ 3x=18\\ x=18:3\\ x=6\\\\ 4-6(x+2)=3-5x\\ 4-6x-12=3-5x\\ -6x-8=3-5x\\ -6x+5x=3+8\\ -x=11\\ x=-11\\\\ (5x+8)-(8x+14)=0\\ 5x+8-8x-14=0\\ -3x-6=0\\ -3x=6\\ x=6:(-3)\\ x=-2\\\\ 2,7+3y=9*(y-2,1)\\ 2,7+3y=9y-18,9\\ 3y-9y=-18,9-2,7\\ -6y=-21,6\\ y=-21,6:(-6)\\ y=3,6$

$0,3(8-3y)=3,2-0,8(y-7)\\ 2,4-0,9y=3,2-0,8y+5,6\\ -0,9y+0,8y=3,2+5,6-2,4\\ -0,1y=6,4\\ y=6,4:(-0,1)\\ y=-64$