Algebra Answers

f:R-{1/2}to R f(x)=(x+3)/(2x-1). IS IT INJECTIVE?

IF f(x1)=f(x2) and then x1=x2 it's injective.
so i want to check f(1)=4 f(2)=5/3. it never become same y value for different x value. but why to check is it injective or not we do f(x1)=f(x2) and then x1=x2?

The Meek brothers are planning a trip around the world. They hope to work some as they go, but
believe that they should have accessible $800 per month so they can live in relative comfort for the year
they plan to be gone. How much should they have in an account earning 6% compounded monthly
when they leave so that they can withdraw the desired $800 each month for twelve months?

The greater of the two angles A = 2tan^-1((2√2)-1) and B=3sin^-1(1/3) + sin^-1(3/5) is?

Twice the difference of a number and 8 is equal to three times the sum of the number and 3. Find the number.

A shopkeeper has two types of coffee beans. The first type sells for $8.20 per kilo, the second for $11.90 per kilo. How many kilograms of the first type must be mixed with 9 kg of the second to produce a blend selling for $10.70 per kilo?
Round-off your answer to two decimal places.

A hurricane plane made a round trip investigation flight. The flight took a total of 5 hours. The pilot flew into the hurricane area at a rate of 144 km/h and returned over the same route at a rate of 88 km/h How many kilometers did the plane fly before it turned back?
Round-off your answer to the nearest unit (i.e. no decimals).

Two trains started from the same station at the same time and traveled in opposite directions. One train's speed was 12 faster than the other. In 5 hours, they were 532 km apart. Find the rate of the faster train. Round-off your answer to one decimal place.

At 11 A.M. two trucks start traveling toward each other at average rates of 51 and 58 kilometers per hour. At the beginning of their trip they were 580 km apart. How long will it take until the trucks pass each other?
Round-off your answer to one decimal place.

A car left an intersection and traveled east at 42 . Another car left the same intersection at the same time and traveled west at 58 . How long will it take for the two cars to be 350 km apart?
Round-off your answer to one decimal place.

The length of a rectangle is 13 feet more than three times the width of the rectangle. The length is 314 feet. Find the width rounded-off to one decimal.