Question

Решите уравнения
$1) : 15x - 6x - 3x = 21.6 \ 2) : 30y - 9y - 12y = 3.42 \ 3) : 5x + 7x - 8x = 0.48 \ 4) : 8y - 3y + 7y = 156$
Help me Please

Answer 1

$15x-6x-3x=21,6 \ 6x=21,6 \ x=3,6 \ 30y-9y-12y=3,42 \ 9y=3,42 \ y=0,38 \ 5x+7x-8x=0,48 \ 4x=0,48 \ x=0,12 \ 8y-3y+7y=156 \ 12y=156 \ y=13$