Question

490:(140-х)*15=105

решите срочно плизз 

Answer 1

490/(140-х)=105/15
490/(140-х)=7
7(140-х)=490
140-х=490/7
140-х=70
-х=70-140
-х=-70
х=70

Answer 2

105:15=7
490:7=70
140-70=70
х=70