Question 289569
a) First note that x-0.3x=x(1-0.3)=x(0.7)=0.7x or in other words, x-0.3x=0.7x



So the complicated expression (x-0.3x)-0.3(x-0.3x)  simplifies to 0.7x-0.3(0.7x). Multiply 0.3 and 0.7 to get 0.21. So we should now have 0.7x-0.21x



Now factor out the GCF 'x' to get x(0.7-0.21) and subtract to get x(0.49)=0.49x



So (x-0.3x)-0.3(x-0.3x) = 0.49x



b) Because 'x' is the original price, this means that 0.49x is the sale price after the discounts. We can think of 0.49 as 1-z=0.49 where 'z' is some unknown percent discount. Solve for 'z' to get z=1-0.49=0.51


So x-0.51x=0.49x which means that we subtracted off 51% of the original price 'x' to get the new sale price 0.49x


So a 30% price reduction followed by another 30% price reduction yields a total of a 51% discount.