Question

(1) 45-(x+8)=31 (2) x-13=56         

Answer 1

45-(x+8)=31
х+8=45-31
х+8=14
х=14-8
х=6

x-13=56     
х=56+13
х=69

Answer 2

x=56+13
x=69

45-x-8=31
-x=31-45+8
-x=-6
x=6