#1
the sum of two numbers is 28.find the numbers if the sum of their squares is a minimum.
#2
two numbers have a difference of 16..find the numbers if the result of adding their sum and their product is a minimum
#3
a uniform border on a framed photograph has the same area as athe photograph.what are the outside dimensions of the border if the dimensions of the photograph are 25 cm by 20 cm .
#4
a bus company carries about 20000 riders per day for a fare of 90 $ a survey indicates that if the fare is decreased.the number of riders will increase by 2000 for every 5$ of decrease.what ticket price would result in the greatest revenue
#6
a lifeguard marks off a rectangular swimming area at a beach with 200 m of rope.what is the greatest area of water she can enclose
1.The sum of n different natural numbers is less than50.the greatest possible value of n is----
2.Let a be the average of all odd prime numbers less than 50.The inreger,most close to a is----
3.If two even natural numbers x,y satisfy equation x的平方加100等于y的平方,x大于y then x乘y等于----
an equation of the line tangent to the graph of f(x)=x(1-2x)^3 at the point (1,-1) is?
A.y= -7x+6
B.y= -6x+5
C.y= -2x+1
D.y= 2x-3
E.y= 7x-8
1、if the product of two positive integers is a prime number what must be the value of the smaller integer?
high tide
2、a mark M,on a cliff is 1.96m below sea level at high tide .at low tide the sea level is 4.18m lower than at high tide.
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| 1.96m
M *
|
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low tide
问题是：at a certain time the sea level is exactly half way between high tide and low tide .how far is the sea level below M at this time?
3、the number 168 and 324,written as the products of thier prime factors ,are
168=2^3 * 3 * 7 324=2^3 * 3^4
问题：the smallest positive integer value of n for which 168n is a multiple of 324?
4、it is required ti find a rational number which is equal to the recurring decimal number 0.73737373……
问题：hence express 0.737373……in the form a/b where a and b are integers?
5、find,in its simplest form,the fraction which is exactly halfway between 13/17 and 14/17?
6、each of the 50 seats at the front of a cinema sells for half the price of one of the remaining seats .there are 200seats altogether and when every seat is sold the takings are $525.
问题：find the price of a seat at the front of the cinema.
7、an athlete walks a distance of 1 km at an average speed of 6 km/h and then,without stopping,runs further distance of 800 meters in 2minutes.
问题：his average speed for the whole journey in km/h.