28.6k views
3 votes
Solve the system of equation please help , I would greatly appreciate it

Solve the system of equation please help , I would greatly appreciate it-example-1
User Long Short
by
5.6k points

2 Answers

3 votes

Answer:

x = 10; y = -1

(10, -1)

D is your answer.

Explanation:

To solve this system of equations, the first step is to to solve for a variable in each equation. I will solve for x in the first one and y in the second.

Part 1: Get x by itself in the first equation

x + 3y = 7

x + 3y - 3y = 7 - 3y

x = 7 - 3y

Part 2: Get y by itself in the second equation

2x - 4y = 24

-4y + 2x - 2x = 24 - 2x

-4y / -4 = (24 - 2x) / -4

y = -6 + 1/2x

New system of equations:

{x = 7 - 3y

{y = -6 + 1/2x

Part 3: Solve for x using substitution

x = 7 - 3(-6 + 1/2x)

x = 7 + 18 - 3/2x

x = 25 - 3/2x

x + 3/2x = 25 - 3/2x + 3/2x

5/2x = 25

(5/2x)(2/5) = 25(2/5)

x = 10

Part 4: Solve for y using substitution

y = -6 + 1/2(10)

y = -6 + 5

y = -1

User Andriy Ivaneyko
by
6.4k points
4 votes

Answer: Your answer is going to be D. (10, -1)


Explanation:

Starting off the equation you want to get rid of either x or y ( I did x first)

Take x+3y=7 and multiply the entire equation by -2 -- -2(x+3y=7)

You get -2x-6y=-14 and then add the two equations together

-2x-6y=-14

2x-4y=24 -- You get -10y = 10

y = -1

You can take the -1 and plug it back into either equation.. ( I did x+3y=7)

x+3(-1)=7 -- x-3=7 -- Add the 3 to get the 10 ( x = 10 )

So you have x = 10 & y = -1

(10,-1)




User Cgee
by
6.1k points