7z+6z-13=130 21t-4t-17=17 помогите

Question

7z+6z-13=130
21t-4t-17=17
помогите

Answer 1

1)7z+6z-13=130
13z-13=130
13z=130+13
13z=143
z=143:13
z=11
2)21t-4t-17=17
17t-17=17
17t=17+17
17t=34
t=34:17
t=2