1) 13a=-5 Make a the subject of the formula by dividing both sides by 13(the coefficient of a) 13a/13=-5/13 Therefore a= -0.385
The second one). 12-b= 12.5 You take the 12 to the other side making b subject of the formula (-b in this case) -b= 12.5-12 -b= 0.5 (You cannot leave b with a negative sign so you will divide both sides by -1 to cancel out the negative sign)
-b/-1= 0.5/-1 Therefore b=-0.5
The third one). -0.1= -10c You will divide both sides by the coefficient of c(number next to c) which is -10 -0.1/-10= -10c/-10
