The astronomy club wants to buy five different eyepieces for a new telescope. the 6-, 12-, and 20-millimeter lenses cost $42.95 each, and the 32- and 40-millimeter lenses cost $57.96 each. estimate the total cost of the lenses to the nearest whole dollar.

$317.66

Step-by-step explanation:

The Total cost of the lenses will be 3 times $42.95 and 2 times $57.96

That is

Cost = 3*42.95+2*57.96

        =128.85 +115.92

        = 244.77

hence cost of all the lenses will be $244.77

d

step-by-step explanation:

hello and welcome!

so, when we see the words "proportional" along with a table, we need to know that we're looking numbers that divide by the same thing.

looking at this table, we simply have to do a trial and error, and divide to see which numbers have the same quotient. if you look at choice a & c, they both have equal quotients for three of the numbers, with one exception, so those can't be the answer. looking at b, there is no similarity, so that can't be it. then, we see d; if you divide all the numbers in the table, you'll see that they all divide by two, which is a proportional relationship, and our answer!

also, always remember that the x will always be the number that goes into y, and somewhere behind this table, is a formula. for this specific table, the formula would be:

since our x-value is being divided by two to get the y-value. and if they were to ask for more numbers in the series, this is the formula you would use to find them.

here's a poem i finished a while ago. i hope you like it and that it inspires you.