13х+12х+15=240 (14х-2х):17=312

Question

13х+12х+15=240
(14х-2х):17=312

Answer 1

1. 25х+15=240
   25х=225
х=9
2.12х:17=312
12х= 312*17
12х=5304
х=442

Answer 2

13x+12x=240-15
25x=225
x=225:25
x=9

(14x-2x):17=312
12x : 17 = 312
12/17х=312
х=312: 12/17х
х= 442