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EleoNora [17]
3 years ago
13

Factorise and solve x^2 + 4x -21 = 0

Mathematics
2 answers:
Korvikt [17]3 years ago
3 0

Answer:

(x + 7) (x - 3)

Step-by-step explanation:

Find 2 numbers that add to 4 and multiply to -21

(x + 7) (x - 3)

Ahat [919]3 years ago
3 0

Answer:

(x+7)(x-4) x=-7,4

Step-by-step explanation:

The factors of -21 that add up to 4 are 7 and -3, so put those as your two second values in your binomials and solve for x, in this case being the negative versions of the second term in the binomial

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Well your question is a little unclear but say there is a bag of marbles containing 3 green marbles and 6 blue marbles then if you wanted to find the ratio of the green marbles it would be 3/9 or 1/3

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OH NO!!! Madeleine’s data has been corrupted, again! Using the incomplete data file below, which she was able to recover from he
-Dominant- [34]

Answer:

a. N=25

b. X[bar]= 60.52

c. Y[bar]= 106.72

d. SSx= 115.24

e. ∑X*∑Y = 4036684

f. SSxy= 202020.3296

g. √(SSx*SSy)= 449.46

Step-by-step explanation:

Hello!

Using the attached data you need to calculate some statistics.

a) N

The sample size is listed under the first column "subject" You can see that 25 subjects qhere studied so N=25.

b.

The mean of set X is equal to X[bar]= ∑X/n= 1513/25= 60.52

∑X is listed in the second table.

c.

The mean of ser Y is Y[bar]= ∑Y/n= 2668/25= 106.72

∑Y is listed in the second table.

d.

Sum of Squares of set X SSx= ∑X²-[(∑X)²/n]= 91682-[(1513)²/25]= 115.24

e.

∑X*∑Y =1513*2668= 4036684

f.

SSxy= (∑X²-[(∑X)²/n]) * (∑Y²-[(∑Y)²/n])= (91682-[(1513)²/25]) * (286482*[(2668)²/25])= 202020.3296

g.

√(SSx*SSy)= √(115.24*1753)= 449.46

I hope you have a SUPER day!

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Please Help!!! 25 points!
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