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
jasenka [17]
3 years ago
11

5.Regarding the equations below. What is the value of x? 5x + 2y = 4 x – 3y = –23

Mathematics
1 answer:
insens350 [35]3 years ago
3 0

Answer:

x=−2

y=7

Step-by-step explanation:

5x+2y=4

x−3y=−23

In order to solve by elimination, coefficients of one of the variables must be the same in both equations so that the variable will cancel out when one equation is subtracted from the other.

5x+2y=4,x−3y=−23

To make 5x and x equal, multiply all terms on each side of the first equation by 1 and all terms on each side of the second by 5.

5x+2y=4,5x+5(−3)y=5(−23)

Simplify.

5x+2y=4,5x−15y=−115

Subtract 5x−15y=−115 from 5x+2y=4 by subtracting like terms on each side of the equal sign.

5x−5x+2y+15y=4+115

Add 5x to −5x. Terms 5x and −5x cancel out, leaving an equation with only one variable that can be solved.

2y+15y=4+115

Add 2y to 15y.

17y=4+115

Add 4 to 115.

17y=119

Divide both sides by 17.

y=7

Substitute 7 for y in x−3y=−23. Because the resulting equation contains only one variable, you can solve for x directly.

x−3×7=−23

Multiply −3 times 7.

x−21=−23

Add 21 to both sides of the equation.

x=−2

The system is now solved.

x=−2,y=7

Graph if needed:

You might be interested in
Find a closed form for the generating function for each of these sequences. (assume a general form for the terms of the sequence
noname [10]
There really is no single "obvious" choice here...

Possibly the sequence is periodic, with seven copies of -1 followed by six copies of 0, or perhaps seven -1s and seven 0s. Or maybe seven -1s, followed by six 0s, then five 1s, and so on, but after a certain point it would seem we have to have negative copies of a number, which is meaningless.

Or maybe it's not periodic, and every seventh value in the sequence is incremented by 1? Who knows?

I'll go ahead and assume the latter case, that the sequence is not periodic, since that's technically somewhat easier to manage. We can assign the following rule to the n-th term in the sequence:

\{a_n\}=\{-1,\ldots,-1,0,\ldots,0,1,\ldots,1,2,\ldots,2,3,\ldots\}
\implies a_n=\left\lfloor\dfrac n7\right\rfloor-1

for n\ge0.

So the generating function for this sequence might be

G(a_n;x)=\displaystyle\sum_{n\ge0}\left(\left\lfloor\frac n7\right\rfloor-1\right)x^n

As to what is meant by "closed form", I'm not sure. Would this answer be acceptable? Or do you need to find a possibly more tractable form for the coefficient not in terms of the floor function?
4 0
3 years ago
joe weighs 20lbs.less yhantwice jeffs weight.if jeff would gain 10lbs.,then together they wouldweigh 250lbs. how much does each
masya89 [10]
So,

Let x represent Joe's weight and y represent Jeff's weight.

"Joe weighs 20 lbs. less than twice Jeff's weight."
x = 2y - 20

"If Jeff would gain 10 lbs., then together they would weigh 250 lbs."
(y + 10) + x = 250

We now have our two open sentences.
x = 2y - 20
(y + 10) + x = 250

Get rid of parentheses.
x = 2y - 20
x + y + 10 = 250

We will use Elimination by Substitution.
2y - 20 + y + 10 = 250

Collect Like Terms.
3y - 10 = 250

Add 10 to both sides.
3y = 260

Divide both sides by 3.
Jeff's\ weight = 86 \frac{2}{3} \ lbs.

Substitute again.
x = 2(86 \frac{2}{3} )-20

Multiply.
x = 173 \frac{1}{3} -20

Subtract.
Joe's\ weight = 153 \frac{1}{3}\ lbs.

Check.

"Joe weighs 20 lbs. less than twice Jeff's weight."
Jeff's weight times two is 173 and one-third.
20 lbs. less than that is 153 and one-third lbs. Check.

"If Jeff would gain 10 lbs., then together they would weigh 250 lbs."
86 and two-thirds + 10 = 96 and two-thirds.
96 and two-thirds + 153 and one-third equals 250 lbs. Check.

Joe's\ weight\ is\ 153 \frac{1}{3} \ lbs.
Jeff's\ weight\ is\ 86 \frac{2}{3} \ lbs.
3 0
3 years ago
The sum of 2 times a number and 8 is 7
My name is Ann [436]

Answer:

The number is -1/2

Step-by-step explanation:

Let x be the number

2x+8 = 7

Subtract 8 from each side

2x+8-8 = 7-8

2x = -1

Divide each side by 2

2x/2 =-1/2

x = -1/2

The number is -1/2

8 0
3 years ago
Read 2 more answers
Richard cuts a piece of wood for a project. The first cut is shown and can be represented by the equation y = 1/2x + 2. The Seco
Morgarella [4.7K]
Since it is parallel, gradient must be the same so it will be 1/2
y=1/2x+c
-7=1/2(0)+c
c=-7
equation is y=1/2x-7
5 0
3 years ago
Read 2 more answers
Help for brainliest answer
guajiro [1.7K]

Step-by-step explanation:

SA=ph+2A, that is, perimeter × height+ twice area

p=21+20+29=70cm

h=22cm

70×22=1540cm

A=1/2 ×20×21=210×2=420

1540+420=1960cm2

8 0
3 years ago
Other questions:
  • Help me please I really need help
    15·1 answer
  • NEED HELP QUICK**
    14·2 answers
  • What are the lengths of the legs of a right triangle in which one acute angle measures 19° and the hypotenuse is 15 units long?
    14·1 answer
  • Can someone help solve for number 3a and 3b
    13·1 answer
  • PLEASE HELPPPP quickly
    11·2 answers
  • How many points did Deven score in his 6th game?
    7·1 answer
  • Please answer correctly! :)
    12·1 answer
  • Richard is frustrated. He knows the line to the right should have a 3 and a 4 in the equation but he can't remember if it is y =
    15·1 answer
  • Funke, Adamu, Shehu, Kwame and Tanko play a game of cards Funke says to Adamu “if you give me 3 cards you will have as many as T
    5·2 answers
  • What is the answer for x+$4.30 =$15.00 ​
    15·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!