Write $\frac 15+\left(\frac 15\right)^2+\left(\frac 15\right)^3+\left(\frac 15\right)^4$ as a decimal

0.2496

Step-by-step explanation:

what you could do is make the all the 1/5 into 2/10's.

then you could multiply all of them (2/10) squared (2/10) cubed and (2/10)^4

now you would have 2/10 4/100 8/1000 16/10000

now you can change it into decimals and add

0.2 +0.04+0.008+0.0016

now all you have to do is add when you do you get 0.2496

there are many ways you could do this problem but this is the most efficient becuause I used another way but it was not helpfull.  

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.