Let x= amount for selling the 90 oranges 3=0.75 90=x Cross multiply. Left side multiplying right and right side multiplying left 3×x=90×0.75 Divide both sides by 3 3×x∕3=90×0.75∕3 x=90×0.75∕3 Change the decimal to the format, whole number ×10a 0.75=75×10−2 (When you move the decimal point to the right its negative to the number of times you moved) ⇒x=90×75×10−2∕3 3 goes into 90, 30 times x=30×75×10−2 30×75=2250 ⇒x=2250×10−2 Now change the whole number ×10a format back to decimal Since the power in 10−2 is negative 2 , you have to move the decimal point to the left two times 2250=2250.0 (Every number has .0 which is not written) 2250.0×10−2=22.50 ⇒x=GH₵22.50