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2 years ago

System of equation by using substitution 3=y+3x -x+3y=29

Mathematics

1 answer:

Marianna [84]2 years ago

5 0

Answer:

x=-2

y=9

Step-by-step explanation:

3=y+3x ---- A

-x+3y=29 ----B

step 1. rearrange equation A, so you have the "y" variable on one side

3=y+3x

-3x -3x

3-3x=y

y=3-3x ---- C

step 2. Substitute equation C into equation B in place of "y"

-x+3(3-3x)=29 ---foil

-x+9-9x=29 -- collect like terms

-10x+9=29

-9 -9

-10x=20

÷-10 ÷-10

x=-2

Step 3. Substitute x=-2 into equation C to find y

y=3-3(-2)

y=3+6

y=9

Check you answer by subsituting x=-2 and y=9 back into equation A and B

You might be interested in

A license plate consists of 2 letters followed by 3 digits. How many license plates are possible if the 1st digit cannot be 0, a

zloy xaker [14]

There are 608400 plates are possible.

If the first is A, we have 26 possibilities:

AA, AB, AC,AD,AE ...................................... AW, AX, AY, AZ.

If the first is B, we have 26 possibilities:

BA, BB, BC, BD, BE .........................................BW, BX,BY,BZ

And so on for every letter of the alphabet.

There are 26 choices for the first letter and 26 choices for the second letter. The number of different combinations of 2 letters is:

26×26=676

The same applies for the three digits.

There are 9 choices for the first as first digit cannot be 0

10 for the second,

10 for the third

9×10×10=900

So for a license plate which has 2 letters and 3 digits, there are:

676 × 900 = 608400 possibilities

To learn more about calculating possibilities from the given link

brainly.com/question/4658834

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8 0

2 years ago

Gibbs Baby Food Company wishes to compare the weight gain of infants using its brand versus its competitor’s. A sample of 40 bab

Leviafan [203]

Answer:

$z=\frac{(7.6-8.1)-0}{\sqrt{\frac{2.3^2}{40}+\frac{2.9^2}{55}}}}=-0.936$

The p value can be founded with this formula:

$p_v =P(z$

Since the p value is higher than the significance level provided of 0.05 we have enough evidence to FAIL to reject the null hypothesis and we can't conclude that the true mean for the Gibbs brand is significantly lower than the true mean for the competitor

Step-by-step explanation:

Information given

$\bar X_{1}=7.6$ represent the mean for Gibbs products