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
Fed [463]
3 years ago
10

How to solve using substitution y=3/4X+5 4x-3y=-1

Mathematics
1 answer:
Pachacha [2.7K]3 years ago
5 0
Please, use parentheses to enclose each fraction:
y=3/4X+5 should be written as <span>y=(3/4)X+5

Let's eliminate the fraction 3/4 by multiplying the above equation through by 4:

4[y] = 4[(3/4)x + 5]
Then 4y = 3x + 20
(no fraction here)

Let 's now solve the system   

4y=3x + 20
4x-3y=-1

We are to solve this system using subtraction.  To accomplish this, multiply the first equation by 3 and the second equation by 4.  Here's what happens:

12y = 9x + 60  (first equation)
16x-12y = -4, or -12y = -4 - 16x (second equation)

Then we have 

 12y = 9x + 60
-12y =-16x - 4

If we add here, 12y-12y becomes zero and we then have 0 = -7x + 56.
Solving this for x:  7x = 56; x=8

We were given equations   
</span><span>y=3/4X+5
4x-3y=-1

We can subst. x=8 into either of these eqn's to find y.  Let's try the first one:

y = (3/4)(8)+5 = 6+5=11

Then x=8 and y=11.

You should check this result.  Subst. x=8 and y=11 into the second given equation.  Is this equation now true?</span>
You might be interested in
14.What is the solution of the system?
Archy [21]

Answer:

14.  x=-2.5,  y = -7

15.  x=28  y = -20

Step-by-step explanation:

14.  Let's solve this system by elimination.  Multiply the first equation by -1.

-1*(4x-y)= -1*(- 3)

-4x +y = 3

Then add this to the second equation.

-4x+y = 3

6x-y= - 8

--------------

2x   = -5


Divide each side by 2

x = -2.5

We still need to find y

-4x+y =3

-4(-2.5) + y =3

10 +y =3

Subtract 10 from each side.

y = 3-10

y = -7


15.I will again use elimination to solve this system, because using substitution will give me fractions which are harder to work with.   I will elimiate the y variable.  Multiply the first equation by 11

11( 5x+6y)= 11*20

55x+66y = 220

Multiply the second equation by -6

-6(9x+11y)=32*(-6)

-54x-66y = -192


Add the modified equations together.

55x+66y = 220

-54x-66y = -192

---------------------------

x = 28

We still need to solve for y

5x+6y = 20

5*28 + 6y =20

140 + 6y = 20

Subtract 140 from each side

6y = -120

Divide by 6

y = -20

3 0
2 years ago
Identify the slope and y-intercept. y=−12x+7
Tatiana [17]

the slope is -12 because y=mx+b and m= slope

7 0
3 years ago
Read 2 more answers
a shade if orange paint is made with 6 parts red paint and 2 parts yellow paint. what percent of the paint is red
Wewaii [24]

Answer:

there is 8 parts total

6/8 red 2/8 yellow

6/8 = 0.75

0.75 X 100 = 75%

4 0
2 years ago
Please help me !!!!!
Lelu [443]

Answer:

thats hard

Step-by-step explanation:

6 0
3 years ago
Read 2 more answers
The probability that rahul succeeds at any given free throw is 70%
MAXImum [283]

Answer:

ok? wahts the question?

Step-by-step explanation:

5 0
3 years ago
Other questions:
  • 4(x+3)-4=8(1/2x+1)<br> What is x
    8·2 answers
  • 12 h x $5/h. find the product list the units explain all of your work.
    15·1 answer
  • Stephanie has pennies, nickels, dimes, and quarters in her piggy bank. The total value of the coins is 0.01(n + 10) + 0.05n + 0.
    9·1 answer
  • PLEEEEEEASE HELP ME:D
    7·1 answer
  • How many grams are in 7 kilometers
    9·2 answers
  • What is the midpoint between points (4,7) and (1,1)?
    12·2 answers
  • If you dig a 6 ft hole how deep is that hole
    8·1 answer
  • Can someone please help super short
    9·2 answers
  • The value of a house is expected to increase by 5% per year over the next several years. The current value of the house is $175,
    15·1 answer
  • K/4 &lt; -4 <br> What could k be???
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!