Question

Determina nr.x stiind ca a-b=6. X*a-x*b+9a-9b=654,13+x-(5*a-5*b)=2011
.7*a-7*b+x=55

Answer 1

X*a-x*b+9a-9b=654
x(a-b)+9(a-b)=654
x*6+9*6=654
6x+54=654
6x=654-54
6x=600
x=600:6
x=100

13+x-(5*a-5*b)=2011
13+x-[5*(a-b)]=2011
13+x-5*6=2011
13+x-30=2011
x=2011-13+30
x=2028

7*a-7*b+x=55
7*(a-b)+x=55
7*6+x=55
42+x=55
x=55-42
x=13