All categories

3 years ago

I need help with 15 please ASAP!!!!!!

Mathematics

1 answer:

Lady bird [3.3K]3 years ago

6 0

Answer:

x must equal 5 and y must equal 2

therefore,

5a + 2b = 23 and

5a - 2b = 7.

I'm gonna take 5a + 2b = 23 and add 7 to each side:

5a + 2b + 7 = 30

and substitute 5a -2b in for 7 on the left side:

5a + 2b + (5a-2b) = 30

10a = 30

a = 3

Now we know a. Now take

5a -2b = 7

and substitute in 3 for a

5*(3) - 2b = 7

15 -2b = 7

8 = 2b

b = 4

a = 3 and b = 4

Step-by-step explanation:

You might be interested in

(x^2+3x-7)(2x-5) write in standard form

Gnoma [55]

Hi there!
The question is asking us to simplify the expression (x² + 3x - 7)(2x - 5) and write the answer in standard form. Here is how you do that -
Original: (x² + 3x - 7)(2x - 5)
Break it apart - [(x² + 3x - 7)(2x)] + [(x² + 3x - 7)(-5)]
Simplify -
2x³ + 6x² - 14x - 5x² - 15x + 35
Now, combine like terms -
2x³ + x² - 29x + 35
Therefore, the answer to your query is 2x³ + x² - 29x + 35. Hope this helps!

7 0

3 years ago

_________________ please help!!!!!!!

jeka94

Answer:

The answer would be C)5

Step-by-step explanation:

The unknown triangle is half of the size of the original triangle, The right side measurement basically hints to the actual answer.

5 0

3 years ago

Y=2x+1<br> How do I put this equation in order pair for a table

Ber [7]

Answer:

I think you would have to draw lines like is the graph book, you will see that they have two axes which is the y and the x.You will then have to fix in numbers and indicate the y= 2x+1.

Step-by-step explanation:

hope it helps

8 0

3 years ago

The national average sat score (for verbal and math) is 1028. if we assume a normal distribution with standard deviation 92, wha

elena55 [62]

Let X be the national sat score. X follows normal distribution with mean μ =1028, standard deviation σ = 92

The 90th percentile score is nothing but the x value for which area below x is 90%.

To find 90th percentile we will find find z score such that probability below z is 0.9

P(Z <z) = 0.9

Using excel function to find z score corresponding to probability 0.9 is

z = NORM.S.INV(0.9) = 1.28

z =1.28

Now convert z score into x value using the formula

x = z *σ + μ

x = 1.28 * 92 + 1028

x = 1145.76

The 90th percentile score value is 1145.76

The probability that randomly selected score exceeds 1200 is

P(X > 1200)

Z score corresponding to x=1200 is

z = $\frac{x - mean}{standard deviation}$

z = $\frac{1200-1028}{92}$

z = 1.8695 ~ 1.87

P(Z > 1.87 ) = 1 - P(Z < 1.87)

Using z-score table to find probability z < 1.87

P(Z < 1.87) = 0.9693

P(Z > 1.87) = 1 - 0.9693

P(Z > 1.87) = 0.0307

The probability that a randomly selected score exceeds 1200 is 0.0307

5 0

3 years ago

Juanita begins to factor an expression as shown.

WARRIOR [948]

Answer:

(x + 6)(x - 3)

Step-by-step explanation:

6 0

3 years ago