You can put this solution on YOUR website! -4x <= -16
let us cosider the 2 cases included here seperately
1st.case is -4x=-16...............2nd.case is -4x<-16...........................
1st.case is -4x=-16
here on lhs we have - 4 multiplying x so when it is transfered to rhs it divides the number there.so we get x=-16/-4 =+4
2nd.case is -4x<-16
here also on lhs we have - 4 multiplying x so when it is transfered to rhs it divides the number there.BUT IN CASE OF INEQUALITIES WHEN A -VE NUMBER IS USED TO MULTIPLY OR DIVIDE THEN THE INEQUALITY GETS REVERSED...FOR EXAMPLE WE KNOW
5>0...BUT WHEN WE MULTIPLY BOTH SIDES WITH -1 SAY WE GET -5<0.THIS IS ONE OF THE FEW MAJOR DIFFERENCES WE HAVE BETWEEN INEQUALITIES AND EQUALITIES
so we get x>-16/-4 ....or...x>+4
hope you understood ..if you want to see more refer my solutions for similar problems posted in the site