Can someone please help me with one or both of these problems, I'm so confused but the assignment is due soon!!

First question: 1270

Second question: 4080

Step-by-step explanation:

Here is the Sum formula:

where n represents the number of terms, and

is the first term, and is the last term.

Let's look at the first question:

k is the first number of the sequence, 5, and 20 is the last number of the sequence.

You can find the first term () by substituting k in the formula for 5.

3(5)+26=15+26=41

You can find the last term () by substituting k for 20 into the formula.

3(20)+26=60+26=86

now, knowing there are 20 terms in total, , and , we can put it into the Sum formula.

Answer to the first question: 1270

Next question:

Even though the given formula uses n as the variable, this problem works the same way as the previous one.

Substitute n in the formula for k, which is 5 to find the first term: 14(5)+29=99

Substitute 20 for n to find the second term: 14(20)+29=309

Now assemble the Sum formula:

Answer to the second question: 4080

you need to give us more information since we can't answer

the 8 in 8,420 is in the thousands place so it's value is 8 thousand.

the 8 in 6,870 is in the hundreds place so it's value is 8 hundred.

divide 8000 by 800 to find the answer:

8000 / 800 = 10

the 8 in 8,420 is 10 times greater than the 8 in 6,870