Tham khảo tài liệu 'gmat exam success episode 2 part 8', ngoại ngữ, ngữ pháp tiếng anh phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | ARITHMETIC 3. If you are subtracting change the subtraction sign to addition and change the sign of the number following to its opposite. Then follow the rules for addition a. -5 -6 -11 b. -12 7 -5 Remember When you subtract you add the opposite. Multiplying and Dividing Integers 1. If an even number of negatives is used multiply or divide as usual and the answer is positive. a. -3 X -4 12 b. -12 -H -6 X 3 6 2. If an odd number of negatives is used multiply or divide as usual and the answer is negative. a. -15 5 -3 b. -2 X -4 X -5 -40 This is helpful to remember when working with powers of a negative number. If the power is even the answer is positive. If the power is odd the answer is negative. Fractions A fraction is a ratio of two numbers where the top number is the numerator and the bottom number is the denominator. Reducing Fractions To reduce fractions to their lowest terms or simplest form find the GCF of both numerator and denominator. Divide each part of the fraction by this common factor and the result is a reduced fraction. When a fraction is in reduced form the two remaining numbers in the fraction are relatively prime. . 6 2 b x 8 a. 9 3 b. 4xy y When performing operations with fractions the important thing to remember is when you need a common denominator and when one is not necessary. Adding and Subtracting Fractions It is very important to remember to find the least common denominator LCD when adding or subtracting fractions. After this is done you will be only adding or subtracting the numerators and keeping the common denominator as the bottom number in your answer. a. 5 3 LCD 15 2 X 3 I 2 X 5 5 X 3 T 3 X 5 6 I 10 16 15 T 15 15 b. y x LCD xy 3 X x I 4 3x 4 y X x xy xy 329 ARITHMETIC Multiplying Fractions It is not necessary to get a common denominator when multiplying fractions. To perform this operation you can simply multiply across the numerators and then the denominators. If possible you can also cross-cancel common factors if they are present
