Method ILet x= annual incomeof means multiplication.Rent is 0.3 of his annual income.1800=0.3×xDivide both sides of the equation by 0.30.31800=xChange the decimal to the form whole number ×10−nWhere n= number of times you have to move the decimal point to get a whole number.0.3=3×10−13×10−11800=xNote: 3 divides itself once, and 1800, 600 times ab1=a−b10−11=10−(−1)=101600×101=x6000=xAnnual income = GH₵6000.00Method IIThe whole income is 1 so you can use proportionality to obtain the income.0.3=18001=0.31×1800=6000