1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
weeeeeb [17]
3 years ago
9

-x+7y=5,-4x+y=-7 System of equations substitution

Mathematics
1 answer:
Leno4ka [110]3 years ago
5 0

Answer:

<h2>x = 2, y = 1 → (2, 1)</h2>

Step-by-step explanation:

\left\{\begin{array}{ccc}-x+7y=5\\-4x+y=-7&\text{add}\ 4x\ \text{to both sides}\end{array}\right\\\\\left\{\begin{array}{ccc}-x+7y=5&(1)\\y=4x-7&(2)\end{array}\right\qquad\text{subtritute (2) to (1)}\\\\-x+7(4x-7)=5\qquad\text{use the distributive property}\\\\-x+(7)(4x)+(7)(-7)=5\\\\-x+28x-49=5\qquad\text{add 49 to both sides}\\\\-x+28x=5+49\qquad\text{combine like terms}\\\\27x=54\qquad\text{divide both sides by 27}\\\\\boxed{x=2}

\text{Put the value of}\ x\ \text{to (2):}\\\\y=4(2)-7\\\\y=8-7\\\\\boxed{y=1}

You might be interested in
5. Daniel arrives at his campsite out of breath from his swim and jog. His sister tells him that he should have swam to the boat
frosja888 [35]

Answer:

hello your question is incomplete attached below is the complete question

answer :

<em>Daniels sister is not correct because the time that will be taken by Daniel will be greater than the initial total time taken by Daniel.</em>

Step-by-step explanation:

<u>First determine the time it will take Daniel to reach the Boat and the jogging time</u>

time = distance / rate

where distance can be calculated using this equation: sin 53° = 400 / x

hence x ( distance ) = 500 ft

rate = 150

therefore Time ( t )  to reach boat = 500 / 150 = 3.33 minutes

Time for jogging ( as calculated ) = 3.69 minutes

therefore total time taken by Daniel = 3.33 + 3.69 = 7.02 minutes

<u>Finally determine if Daniel's sister is correct that he should have swam to the boat ramp and then jogged </u>

lets assume Distance to swim  =  x  ( according his sister )

determine the value of x = \sqrt{400^2 + 1400^2 }   therefore X = 1456.02 feet

∴

Total time to be taken if Daniel follows his sister's instruction  = 1456.02 / 150 = 9.71 minutes

<em>Daniels sister is not correct because the time that will be taken by Daniel will be greater than the initial total time taken by Daniel.</em>

<u />

<u />

<u />

6 0
3 years ago
The shelf is made of 3 pieces of wood, each 0.3 meter wide. There is also 0.05 meter of space between the shelf and the wall on
lutik1710 [3]
Since there are 2 sides to the shelf, there is 0.05*2=0.05+0.05=0.1 meters of space between the shelf and wall in total. Next, since each piece of wood is 0.3 meters wide and we have 3 of them, the total width of the wood is 0.3+0.3+<something>
Note that <width of wood>+<space between shelf and well> =width of closet
I challenge you to finish this on your own - good luck, and feel free to ask with any further questions! 

8 0
3 years ago
As x → − ∞ , f ( x ) = − 3 . As x → ∞ , f ( x ) = − 3
Ludmilka [50]

Answer:

hi

Step-by-step explanation:

4 0
2 years ago
A grocery store had 38 employees, but then they hired 4 more people. What is the percent change in their staff?
gizmo_the_mogwai [7]

The percentage change in the staff strength of the grocery store is 10.53%.

<h3>How to find the percentage change?</h3>

We are given;

Number of employees in store = 38 employees

Number of additional people hired = 4 employees

Thus, percentage change in their staff is;

4/38 * 100% = 10.53%

Thus, the percentage change in the staff strength of the grocery store is 10.53%.

Read more about Percentage change at; brainly.com/question/2085058

#SPJ1

7 0
2 years ago
EMERGENCY Add using the number line.
kumpel [21]
The Answer is -3 it would be easier to use a calculator for that than this
3 0
3 years ago
Other questions:
  • There are three motors available to repair Ralph’s vacuum cleaner. Motor #1 has a 65% chance of breaking by the end of the week.
    10·1 answer
  • 1400 concert tickets were sold for the festival. tickets cost $25 for covered pavilion seats and $10 for lawn seats. total recei
    5·1 answer
  • What value is equivalent to 30 − 23 × 3?
    13·2 answers
  • Which function represents a horizontal shift of f(x) = 5x by 4 units to the right?
    5·1 answer
  • Find all roots (zeros) please show work!!
    10·1 answer
  • How long does it take the snail to crawl 73 inches?
    6·1 answer
  • What is <img src="https://tex.z-dn.net/?f=%28%5Cfrac%7B1%7D%7B5%7D%20%29%5E%7B4%7D" id="TexFormula1" title="(\frac{1}{5} )^{4}"
    12·1 answer
  • P: It's sunny.
    14·1 answer
  • Which expression is equivalent to the expression shown below?
    6·1 answer
  • A candy bar box is in the shape of a triangular prism. The volume of the box is 3,240 cubic centimeters. A triangular prism is s
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!