gmat數(shù)學(xué)精解之算術(shù)
如何備考gmat數(shù)學(xué)考試，對于很多計(jì)劃參加gmat考試的人來說，要想在gmat考試中獲取好的成績，gmat數(shù)學(xué)考試的成敗很重要，下面就來看看備考gmat數(shù)學(xué)考試的時(shí)候需要掌握的一些算術(shù)知識。
一.整數(shù)：integer，whole number 因子：factor or divisor
If x and y are integers and x0,x is a divisor of y provided that y=xn for some integer n. In this case y is also said to be divisible by x or to be a multiple of x. For example, 7 is a divisor or factor of 28 since 28=74, but 8 is not a divisor of 28 since there is no integer n such that 28=8n.Divisible adj.可以被整除的 multiple n.倍數(shù)
2.商和余數(shù)：quotients and remainders
余數(shù)和商都可以為0
3.奇數(shù)和偶數(shù)：odd and even integers
奇數(shù)和偶數(shù)都可以是負(fù)數(shù);零一定是偶數(shù)
4.質(zhì)數(shù)和合數(shù)：prime numbers and composite numbers
A prime number is a positive integer that has exactly two different positive divisors，1 and itself. For example, 2,3,5,7,11, and 13 are prime numbers, but 15 is not, since 15 has four different positive divisors, 1, 3, 5, and 15. The number 1 is not a prime number, since it has only one positive divisor. Every integer greater than 1 is either prime or can be uniquely expressed as a product of prime factors. For example, 14= , 81= , and 484= .
注:除了1和其本身外,還有其他因子的數(shù)叫合數(shù)。最小的質(zhì)數(shù)為2，最小的合數(shù)為4，在討論質(zhì)數(shù)和合數(shù)時(shí)，都指正數(shù)。1和0既不是質(zhì)數(shù)，也不是合數(shù)。
5.整數(shù)中的重要概念：
Perfect square耆?椒絞??釗? = 32
Perfect cube 完全立方數(shù)，諸如8 = 23
the greatest common divisor 最大公約數(shù)
幾個(gè)數(shù)所公有的最大因子稱最大公約數(shù)，諸如：48與36的公因子有1，2，3，4，6，12，其中12為最大公約數(shù)。
the least common multiple最小公倍數(shù)
幾個(gè)數(shù)所公有的最小倍數(shù)稱最小公倍數(shù)，諸如：3，7和14的最小公倍數(shù)為42。
連續(xù)正整數(shù)的算術(shù)平均值也是首項(xiàng)和末項(xiàng)的算術(shù)平均值。
同理，連續(xù)奇數(shù)與連續(xù)偶數(shù)的算術(shù)平均值也是首項(xiàng)和末項(xiàng)的算術(shù)平均值。
the properties of the number of factors因子個(gè)數(shù)的特性：
1)當(dāng)一個(gè)正整數(shù)n有奇數(shù)個(gè)因子，則n必為一完全平方數(shù)。
2)除了n的平方根為其中一個(gè)因子外，小于n的平方根的因子與大于n的平方根的因子數(shù)相同。
3)當(dāng)某一正整數(shù)n有偶數(shù)因子時(shí)，則n必不是完全平方數(shù)，且大于n的平方根的因子與小于其的因子數(shù)相同。
因子數(shù)的求解公式：將整數(shù)n分解為質(zhì)因子相乘的形式，然后將每個(gè)質(zhì)因子的冪分別加1之后連乘所得的結(jié)果就是n的因子的個(gè)數(shù)。 分頁標(biāo)題#e#
例：80的因子個(gè)數(shù)可以如下方式求得：80 = 2 45，則因子個(gè)數(shù)為= 10
如何備考gmat數(shù)學(xué)考試，對于很多計(jì)劃參加gmat考試的人來說，要想在gmat考試中獲取好的成績，gmat數(shù)學(xué)考試的成敗很重要，下面就來看看備考gmat數(shù)學(xué)考試的時(shí)候需要掌握的一些算術(shù)知識。
一.整數(shù)：integer，whole number 因子：factor or divisor
If x and y are integers and x0,x is a divisor of y provided that y=xn for some integer n. In this case y is also said to be divisible by x or to be a multiple of x. For example, 7 is a divisor or factor of 28 since 28=74, but 8 is not a divisor of 28 since there is no integer n such that 28=8n.Divisible adj.可以被整除的 multiple n.倍數(shù)
2.商和余數(shù)：quotients and remainders
余數(shù)和商都可以為0
3.奇數(shù)和偶數(shù)：odd and even integers
奇數(shù)和偶數(shù)都可以是負(fù)數(shù);零一定是偶數(shù)
4.質(zhì)數(shù)和合數(shù)：prime numbers and composite numbers
A prime number is a positive integer that has exactly two different positive divisors，1 and itself. For example, 2,3,5,7,11, and 13 are prime numbers, but 15 is not, since 15 has four different positive divisors, 1, 3, 5, and 15. The number 1 is not a prime number, since it has only one positive divisor. Every integer greater than 1 is either prime or can be uniquely expressed as a product of prime factors. For example, 14= , 81= , and 484= .
注:除了1和其本身外,還有其他因子的數(shù)叫合數(shù)。最小的質(zhì)數(shù)為2，最小的合數(shù)為4，在討論質(zhì)數(shù)和合數(shù)時(shí)，都指正數(shù)。1和0既不是質(zhì)數(shù)，也不是合數(shù)。
5.整數(shù)中的重要概念：
Perfect square耆?椒絞??釗? = 32
Perfect cube 完全立方數(shù)，諸如8 = 23
the greatest common divisor 最大公約數(shù)
幾個(gè)數(shù)所公有的最大因子稱最大公約數(shù)，諸如：48與36的公因子有1，2，3，4，6，12，其中12為最大公約數(shù)。
the least common multiple最小公倍數(shù)
幾個(gè)數(shù)所公有的最小倍數(shù)稱最小公倍數(shù)，諸如：3，7和14的最小公倍數(shù)為42。
連續(xù)正整數(shù)的算術(shù)平均值也是首項(xiàng)和末項(xiàng)的算術(shù)平均值。
同理，連續(xù)奇數(shù)與連續(xù)偶數(shù)的算術(shù)平均值也是首項(xiàng)和末項(xiàng)的算術(shù)平均值。
the properties of the number of factors因子個(gè)數(shù)的特性：
1)當(dāng)一個(gè)正整數(shù)n有奇數(shù)個(gè)因子，則n必為一完全平方數(shù)。
2)除了n的平方根為其中一個(gè)因子外，小于n的平方根的因子與大于n的平方根的因子數(shù)相同。
3)當(dāng)某一正整數(shù)n有偶數(shù)因子時(shí)，則n必不是完全平方數(shù)，且大于n的平方根的因子與小于其的因子數(shù)相同。
因子數(shù)的求解公式：將整數(shù)n分解為質(zhì)因子相乘的形式，然后將每個(gè)質(zhì)因子的冪分別加1之后連乘所得的結(jié)果就是n的因子的個(gè)數(shù)。 分頁標(biāo)題#e#
例：80的因子個(gè)數(shù)可以如下方式求得：80 = 2 45，則因子個(gè)數(shù)為= 10
