Question

8x-12=5340;
255:(x+13)=17.

Answer 1

1) 8х-12=5340

8х=5340+12

8х=5352

х=5352:8

х=669

8·669-12=5340

5340=5340

2) 255:(х+13)=17

х+13=255:17

х+13=15

х=15-13

х=2

255:(2+13)=17

17=17