Using the properties of inequalties, write down the inequality that you will get if you:
a) add the number -5; 2.7; 7; to both sides of the inequality 18> -7
b) subtract the number 2; 12; -5; from both sides of the inequality 5 > -3
c) multiply both sides of the inequality - 9 < 21 by the number 2; -1; -1/3
d) divide both sides of the inequality 15 > -6 by the number 3; -3; -1