I am just learning variable expressions. My homework is to write a variable expression for each word phrase;

example :

the number of minutes in s seconds
the cost of x cartons of juice at \$.75 each
And etc.

I don't understand it

Thank you
Brittany
8th grader

Hi Brittany,

Sometimes it helps to try some numbers for the variable. Let's do the second example first.

Numeric value for x Cost of x cartons of juice
1\$0.75
2\$1.50
3\$2.25
4\$3.00

That is one carton of juice costs \$0.75
Two cartons of juice cost \$0.75 + \$0.75 = 2(\$0.75) = \$1.50
Three cartons of juice cost \$0.75 + \$0.75 + \$0.75 = 3(\$0.75) = \$2.25

Each time you multiply \$0.75 by the value for x, in other words, x(\$0.75). Thus

the cost of x cartons of juice at \$0.75 each is x(\$0.75)

For the first problem, what values if s make the calculation easy?

If s is 60 seconds then the nunber of minutes is 1.
If s is 120 seconds then the nunber of minutes is 2.
If s is 180 seconds then the nunber of minutes is 3.
If s is 90 seconds then the nunber of minutes is 1 1/2.

This time what you are doing is dividing the number if seconds by 60. Thus

the number of minutes in s seconds is  s/60

Now try the rest of the problems.
Penny

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