Question

а) 13х - 2х = 121;
б) 5у + 30у = 17640

Answer 1

а) 11х=121
х=11
б)35у=17640
у=504

Answer 2

$13x - 2x = 121 \ 11x = 121 \ x = 121 div 11 \ x = 11$
$5y + 3y = 17640 \ 35y = 17640 \ y = 17640 div 35 \ y = 504$