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31 votes
31 votes
Solve the following system of equations:

x = 40 + 3y
6x + 13y = 550

(5, 55)
(10, 70)
(70, 10)
(100, 20)

User Vanya Rachel
by
2.0k points

2 Answers

7 votes
7 votes

Final answer:

Solving the system of equations by substitution, the solution is found to be x = 70 and y = 10, corresponding to the option (70, 10).

Step-by-step explanation:

To solve the system of equations given in the question, we substitute the value of x from the first equation into the second equation and solve for y:

  • x = 40 + 3y
  • 6x + 13y = 550

Substitute x in the second equation:

  1. 6(40 + 3y) + 13y = 550
  2. 240 + 18y + 13y = 550
  3. 31y + 240 = 550
  4. 31y = 310
  5. y = 10

Once we have the value of y, we can substitute it back into the first equation to find x:

  1. x = 40 + 3(10)
  2. x = 40 + 30
  3. x = 70

Hence the solution to the system is x = 70 and y = 10, which corresponds to option (70, 10).

User Puran
by
3.2k points
8 votes
8 votes
(10, 70)

Change the top equation to x-3y=40. Then multiply each value in that equation by 6 to make it 6x-18y=240. Then subtract each value. You should be left with -31y = -310, making y=10.
User Krii
by
2.9k points