Question

Tìm X biết :

X x 5 + X x 7 +X x 4 -X x 2 - X x 3 = X + 90 

Answer 1

=>Xx (5+7+4-2-3)=x+90

=>Xx11=X+90

=>Xx11-X=90

=>Xx(11-1)=90

=>Xx10=90

=>X=9 

Answer 2

x(5+7+4-2-3)=x+90

11x=x+90

10x=90\(\Rightarrow\)x=9