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3 years ago

HELP simple question

Mathematics

2 answers:

lawyer [7]3 years ago

5 0

Answer:

I think it’s step 2 where she distributed the exponents incorrectly but she got it right so since no explanation is really needed then I guess it’s step 2.

step 1 where she divided 5 on both sides. Step 3 is also correct since the answer is 0. so step 2 had the mistake.

Butoxors [25]3 years ago

5 0

I’m gonna guess step 1 (x+7)^2=49 because the math doesn’t make sense on that

You might be interested in

If n(A-B)=18,n(AuB)=70 and n(AnB)=25 then find n(B)

svp [43]

n(A-B) denotes elements which are in A but not in B

n(Au B) denotes elements in A and B

n(AnB) denotes elements that are common in A and B

Now I will add one more set

n(B-A) which denotes elements in B but not in A

So, n(AuB) = n(A-B) + n( B-A) +n(AnB)

70 = 18 +n(B-A) + 25

70 = 43 + n(B-A)

n(B-A) = 70-43

n(B-A) = 27

So, n(B) = n( B-A) + n( AnB)

= 27+25

= 52

4 0

3 years ago

Dont really understand how to do this

bija089 [108]

Answers:

$t_{10} = -22 \ \text{ and } S_{10} = -85$

========================================================

Explanation:

$t_1 = \text{first term} = 5\\t_2 = \text{first term}-3 = t_1 - 3 = 5-3 = 2$

Note we subtract 3 off the previous term (t1) to get the next term (t2). Each new successive term is found this way

$t_3 = t_2 - 3 = 2-3 = -1\\t_4 = t_3 - 3 = -1-3 = -4$

and so on. This process may take a while to reach $t_{10}$

There's a shortcut. The nth term of any arithmetic sequence is

$t_n = t_1+d(n-1)$

We plug in $t_1 = 5 \text{ and } d = -3$ and simplify

$t_n = t_1+d(n-1)\\t_n = 5+(-3)(n-1)\\t_n = 5-3n+3\\t_n = -3n+8$

Then we can plug in various positive whole numbers for n to find the corresponding $t_n$ value. For example, plug in n = 2

$t_n = -3n+8\\t_2 = -3*2+8\\t_2 = -6+8\\t_2 = 2$

which matches with the second term we found earlier. And,

$tn = -3n+8\\t_{10} = -3*10+8\\t_{10} = -30+8\\t_{10} = \boldsymbol{-22} \ \textbf{ is the tenth term}$

---------------------

The notation $S_{10}$ refers to the sum of the first ten terms $t_1, t_2, \ldots, t_9, t_{10}$

We could use either the long way or the shortcut above to find all $t_1$ through $t_{10}$ . Then add those values up. Or we can take this shortcut below.

$Sn = \text{sum of the first n terms of an arithmetic sequence}\\S_n = (n/2)*(t_1+t_n)\\S_{10} = (10/2)*(t_1+t_{10})\\S_{10} = (10/2)*(5-22)\\S_{10} = 5*(-17)\\\boldsymbol{S_{10} = -85}$

The sum of the first ten terms is -85

-----------------------

As a check for $S_{10}$ , here are the first ten terms:

t1 = 5
t2 = 2
t3 = -1
t4 = -4
t5 = -7
t6 = -10
t7 = -13
t8 = -16
t9 = -19
t10 = -22

Then adding said terms gets us...

5 + 2 + (-1) + (-4) + (-7) + (-10) + (-13) + (-16) + (-19) + (-22) = -85

This confirms that $S_{10} = -85$ is correct.

6 0

2 years ago

Which of the following graphs is the solution set of -10 < 3x - 4 < 8?

sveticcg [70]

Answer:

The First Graph -2○ and 4○

Step-by-step explanation:

Because these numbers aren't included in the solution.

8 0

3 years ago

what are two practical products you could add to find 990 x 37 ; 297 693 2970 6930 69300 6330 29700

VMariaS [17]

First evaluate 990 x 37.
990 x 37 = 36630

Test the given numbers to find the pair that adds up to 36630.
Test 297.
The missing pair will be
36630 - 297 = 36333
Will not work

Test 693.
36630 - 693 = 35937
Will not work

Test 2970.
36630 - 2970 = 33660
Will not work

Test 6930
36630 - 6930 = 29700
This works, because 6930 + 29700 = 36630.

Answer: 6930 and 29700.

8 0

3 years ago

Whats the answer to -3a+8-8(7-2a)

Serga [27]

Answer:3.1875

Step-by-step explanation: Simplifying

-3 + 8 + -8(7 + -2a) = 0

-3 + 8 + (7 * -8 + -2a * -8) = 0

-3 + 8 + (-56 + 16a) = 0

Combine like terms: -3 + 8 = 5

5 + -56 + 16a = 0

Combine like terms: 5 + -56 = -51

-51 + 16a = 0

Solving

-51 + 16a = 0

Solving for variable 'a'.

Move all terms containing a to the left, all other terms to the right.

Add '51' to each side of the equation.

-51 + 51 + 16a = 0 + 51

Combine like terms: -51 + 51 = 0

0 + 16a = 0 + 51

16a = 0 + 51

Combine like terms: 0 + 51 = 51

16a = 51

Divide each side by '16'.

a = 3.1875

Simplifying

a = 3.1875

5 0

3 years ago

Read 2 more answers