Tom can do a job in 4 hours while Sam can do it in 6 hours. How many hours would it take to complete this job if they work together?

12/5hours=2.4 hours

Step-by-step explanation:

Sam:6hours

Tom:4hours

This is a rate problem

Sam's rate is one job completed in 6 hours which is 1/6

Tom's rate is one job completed in 4 hours which is 1/4

Together, they could complete 1/4+1/6 of the job in y hours

We are trying to find the rate at which Sam and Tom could complete the job together, or one job in x days, for a rate of 1/y

1/4+1/6=1/y

The least common denominator is 12y

Multiplying through by the LCD which gives:

12y(1/4)+ 12y (1/6)= 12y (1/y)

3y + 2y=12

5y = 12

y=12/5 hours=2.4hours

Therefore it will take 12/5 hours or 2.4 hours to complete the job if they work together

x > 1.3

step by step:

8.5−0.9x> 9.8−1.9x

step 1: simplify both sides of the inequality.

−0.9x+8.5> −1.9x+9.8

step 2: add 1.9x to both sides.

−0.9x+8.5+1.9x> −1.9x+9.8+1.9x

1x+8.5> 9.8

step 3: subtract 8.5 from both sides.

1x+8.5−8.5> 9.8−8.5

1x> 1.3

step 4: divide both sides by 1.

1x/1 > 1.3/1

3

step-by-step explanation:

in standard form:

a= dictionaries

b= maps

you have to buy 3 dictionaries, so put a 3 next to the a (dictionaries) so that you can multiply them by each other.

a3+b= 60 (the amount of money you have)

we already know the cost of a=15 so replace a with $15

($15 x 3)+b=60

multiply 15 and 3 to get $45 and replace it with $45

45+b=60

and then replace b with 15 to get the total:

45+15=60

that means you have $15 left after buying 3 dictionaries.

15 divided by the cost of a map ($5) equals 3.

so you can buy 3 maps.

sorry if it was confusing!