Tham khảo tài liệu 'the sat math section 4', ngoại ngữ, anh ngữ phổ thông phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | THE SAT MATH SECTION 39. Marguerite is remodeling her bathroom floor. Each imported tile measures 1j inch by 14 inch. What is the area of each tile a. 1787 square inches b. 1 square inches c. 2 1 square inches d. 3737 square inches e. 47127 square inches 40. If Deirdre walks from Point A to Point B to Point C at a constant rate of 2 mph without stopping what is the total time she takes x miles y miles ABC a. x y X 2 b. 2x 2y c. xy 2 d. x y 2 e. xy2 157 THE SAT MATH SECTION Five-Choice Answers 1. c. After reading the problem you realize that the amount of robins at the feeder is related to the number of cardinals. When this is the case you have to set up a legend or a key defining the number of cardinals. Then relate it to the number of robins. Step 1 Let x number of cardinals Let 3x number of robins Step 2 Now you have to come up with a formula to solve for x. number of cardinals number of robins total number of birds x 3x 20 4x 20 x 5 Step 3 Take your answer for x and substitute it back into the legend. x number of cardinals 3x number of robins 5 number of cardinals 3 5 number of robins 15 number of robins The answer is choice c. 2. b. You should realize that since the question asks for a factor of 4x2 - 9 you have to begin factoring this expression. The question you should ask yourself is Which method of factoring should I use Looking at the expression 4x2 - 9 you should notice that there are no common factors between the two terms. Therefore you cannot factor out a common factor. Also this is not a trinomial. Thus you cannot factor this expression like a trinomial. The method that you have to use in factoring is the difference of two perfect squares. There are a couple of hints in the problem that clue you in on this. First there are only two terms. Second the operation between the two terms is subtraction. Remember the word difference means subtraction. Now we have to factor 4x2 - 9. 4x2- 9 2x 3 2x - 3 This is now factored and we can see that one of the factors
