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4 years ago

With the substitution method, which variable should you solve for first?

1 answer:

5 0

It really does not matter, I tend to solve for x first simply because it comes before y, but you do whatever is easier for you.

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Guys please help me out ASAP, Due today. I

Mice21 [21]

Answer:

$T_7 = 11$

$T_n = 2n- 3$

Step-by-step explanation:

Given

$S_n = n^2 -2n$

$T_n = S_n - S_{n-1}$

Solving (a): T7

Substitute 7 for n in $T_n = S_n - S_{n-1}$

$T_7 = S_7 - S_{7-1}$

$T_7 = S_7 - S_6$

Calculate S7 and S6

$S_n = n^2 -2n$

$S_7 = 7^2 - 2 * 7 = 35$

$S_6 = 6^2 - 2 * 6 = 24$

So:

$T_7 = 35 -24$

$T_7 = 11$

Solving (b): Tn

$T_n = S_n - S_{n-1}$

Where $S_n = n^2 -2n$

Calculate $S_{n-1}$

We have:

$S_{n-1} =(n-1)^2 - 2(n-1)$

Open brackets

$S_{n-1} = n^2 -2n + 1 -2n +2$

$S_{n-1} = n^2 -2n-2n + 1 +2$

$S_{n-1} = n^2 -4n + 3$

So:

$T_n = S_n - S_{n-1}$

$T_n = n^2 - 2n - (n^2 -4n + 3)$

$T_n = n^2 - 2n - n^2 +4n - 3$

Collect Like Terms

$T_n = n^2 - n^2- 2n +4n - 3$

$T_n = 2n- 3$

5 0

3 years ago

What's 32.88 divided by 0.6

otez555 [7]

It’s 54.8 I’m pretty sure
(I hope this helps!)

8 0

3 years ago

Read 2 more answers

Please help solve <br><br> -2x - 4 - 7 = - 3x - 15

valentina_108 [34]

Answer:

x = -4

Step-by-step explanation:

-2x-11=-3x-15

x - 11 = -15

x = -4

8 0

3 years ago

2) A gym charges a $30 membership fee and $10 per month. Write an

kari74 [83]

C = 10m + 30, where C is total cost and m is # of months

C = 10(5) + 30

C = 50 + 30

C = $80

$160 = 10m + 30

160 - 30 = 10m

130/10 = m

m = 13 months

Hope that helps

5 0

3 years ago

El has $10.25 to spend at

Nonamiya [84]

No . but she can buy 2 of the books but not all 3

5 0

4 years ago