Alex and lara have $21.00 each to spend at a book fair, where all students receive a 35% discount. they both want to purchase a copy of the same book, which normally sells for $28.50 plus 10% sales tax. to check if he has enough to purchase the book, alex takes 35% of $28.50 and subtracts that amount from the normal price. he takes 10% of the discounted selling price and adds it back to find the purchase amount. lara takes 65% of the normal purchase price and then computes 110% of the reduced price. is alex correct? is lara correct? do they have enough money to purchase the book? explain your answer using complete sentences, and show your work.

proofs involving isosceles triangles often require special consideration because an isosceles triangle has several distinct properties that do not apply to normal triangles.(more about triangle types) therefore, when you are trying to prove that two triangles are congruent, and one or both triangles, are isosceles you have a few theorems that you can use to make your life easier.

step-by-step explanation:

an isosceles triangle has two congruent sides and two congruent angles. the congruent angles are called the base angles and the other angle is known as the vertex angle. ∠bac and ∠bca are the base angles of the triangle picture on the left. the vertex angle is ∠abc