Ask question

Ask question

All categories

2 years ago

9

Solve for both systems: y+7z=22 and 8y + 7z = 127

2 answers:

7nadin3 [17]2 years ago

5 0

Manipulate the first equation to
y = 22-7z

Then substitute in the second to find z
8(22-7z) + 7z = 127
176-56z+7z = 127
-49z = -49
z = 1

So y = 22-7(1) = 22-7 = 15

y = 15; z = 1

Zielflug [23.3K]2 years ago

5 0

This is easy, one way is to subsitute
y+7z=22 and
8y+7z=127

y+7z=22
subtract y
7z=22-y

8y+7z=127
subtract 8y
7z=127-8y
subsitute
22-y=7z=127-8y
22-y=127-8y
add y to both sides
22=127-7y
subtract 127
-105=-7y
divide by 7
15=y
subsitute
15+7z=22
subtract 15
7z=7
divide 7
z=1

y=15
z=1

You might be interested in

Which of the following shows the correct solution steps and solution to 7x-4= -18?

Serga [27]

7x - 4 = -18
7x = -14
x = -2

3 0

3 years ago

Read 2 more answers

A Ferris wheel at the local fair has a diameter of 36 feet and a midline of 15 feet. This Ferris wheel makes one revolution ever

AVprozaik [17]

Answer:

Hold on let me seee!!!!!!!

5 0

3 years ago

A certain test preparation course is designed to help students improve their scores on the LSAT exam. A mock exam is given at th

OlgaM077 [116]

Answer:

Interval [16.34 , 21.43]

Step-by-step explanation:

First step. <u>Calculate the mean</u>

$\bar X=\frac{(23+18+23+12+13+23)}{6}=18.666$

Second step. <u>Calculate the standard deviation</u>

$\sigma =\sqrt{\frac{(23-18.666)^2+(18-18.666)^2+(23-18.666)^2+(12-18.666)^2+(13-18.666)^2+(23-18.666)^2}{6}}$

$\sigma=\sqrt\frac{18.783+0.443+18.783+44.435+5.666+18.783}{6}$

$\sigma=\sqrt{17.815}=4.22$

As the number of data is less than 30, we must use the t-table to find the interval of confidence.

We have 6 observations, our level of confidence DF is then 6-1=5 and we want our area A to be 80% (0.08).

We must then choose t = 1.476 (see attachment)

Now, we use the formula that gives us the end points of the required interval

$\bar X \pm t\frac{\sigma}{\sqrt n}$

where n is the number of observations.

The extremes of the interval are then, rounded to the nearest hundreth, 16.34 and 21.43

6 0

2 years ago

30 points pls helppp

Phoenix [80]

Answer:

(y + 1) = 3( x +2)

Step-by-step explanation:

from equation,

y - y1 = m( x - x1)

given x1=2, y1= -1

m = 3 (slope)

substitute

y - (-1) = 3( x - 2)

ans: y+1= 3(x+2)

3 0

2 years ago

The distance between City A and City B is 250 miles. A length of 2.3 feet represents this distance on a certain wall map. City C

masya89 [10]

The distance between city C and city D is 450 miles.

<u>Solution:</u>

Given, The distance between City A and City B is 250 miles.

A length of 2.3 feet represents this distance on a certain wall map.

City C and City D are 4.14 feet apart on this map.

We have to find what is the actual distance between City C and City D?

Now, distance between a and b is 250 miles ⇒ 2.3 feet on map

Then, distance between c and d be n miles ⇒ 4.14 feet on map.

Now, by chris cross method.

250 x 4.14 = 2.3 x n miles.

2.3n = 1035

n = 450

Hence, the distance between city C and city D is 450 miles.

8 0

3 years ago