Tham khảo tài liệu 'math test english 1', ngoại ngữ, anh ngữ phổ thông phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | ------------------------------ ACT MATH TEST PRACTICE -------------------------------------- 2. 9 6 2 X 4 - 32 9 6 8 - 32 9 14 - 9 23 - 9 14 Fractions Addition of Fractions To add fractions they must have a common denominator. The common denominator is a common multiple of the denominators. Usually the least common multiple is used. Example -3- 7 The least common denominator for 3 and 7 is 21. y X ỷ 7 X - Multiply the numerator and denominator of each fraction by the same number so that the denominator of each fraction is 21. 8 7j- 21 21 Add the numerators and keep the denominators the same. Simplify the answer if necessary. Subtraction of Fractions Use the same method for multiplying fractions except subtract the numerators. Multiplication of Fractions Multiply numerators and multiply denominators. Simplify the answer if necessary. Example 3 1 JL 4 X 5 20 Division of Fractions Take the reciprocal of flip the second fraction and multiply. 1 - 3 44 4 3 4 3 X 3 9 144 ----------------------------- ACT MATH TEST PRACTICE -------------------------------------- Examples 1. I 5 2. - 3 3. IX 8 4. I 7 Solutions a 1 X 5 2 X 3 3 X5 5 X3 5 . _6_ J 15 15 15 2 9 X 2 3 X 5 2. 10 X2 - 4 X5 8_ _3_ 20 20 20 o 47 28 7_ 3. 5 X 8 40 10 4. 4 X ị ị Exponents and Square Roots An exponent tells you how many times to the base is used as factor. Any base to the power of zero is one. Example 140 1 53 5 X 5 X 5 125 34 3 X 3 X 3 X 3 81 112 11 X 11 121 Make sure you know how to work with exponents on the calculator that you bring to the test. Most scientific calculators have a yx or xy button that is used to quickly calculate powers. When finding a square root you are looking for the number that when multiplied by itself gives you the number under the square root symbol. V25 5 V64 8 VĨ69 13 145 ACT MATH TEST PRACTICE Have the perfect squares of numbers from 1 to 13 memorized since they frequently come up in all types of math problems. The perfect squares in order are 1 4 9 16 25 36 49 64 81
