Solve the following system of equations. x − 2y = 5 −3x + 2y = 7 A. x = 3, y = −1 B. x = 11, C. x = −6, D. x = 3, y = 1

2 answers:

8 0

x - 2y = 5
-3x + 2y = 7
-----------------add
-2x = 12
x = 12/-2
x = -6

-3x + 2y = 7
-3(-6) + 2y = 7
18 + 2y = 7
2y = 7 - 18
2y = - 11
y = -11/2

solution is : (-6,-11/2)...x = -6 and y = -11/2

maw [93]3 years ago

3 0

Answer: C) x=-6

Step-by-step explanation: we can solve a system of equation by different methods, in this case we will use substitution:

First we isolate the x from the first equation:

x=5+2y

then we replace it in the second equation:

-3x+2y=7

-3(5+2y)+2y=7

now we solve and isolate the y

-15-6y+2y=7

-15-4y=7

-4y=7+15

-4y=22

y=22/-4

y=-11/2

now we replace the value of y in the first equation:

x=5+2y

x=5+2(-11/2)

x=5-11

x=-6

You might be interested in

Help me answer this.. plz

Fudgin [204]

Answer:

2 $\frac{1}{30}$

Step-by-step explanation:

First thing you gotta do is find the common denominator.

Do this by listing factors of the denominators:

5- 5, 10, 15, 20, 25, 30

6- 6, 12, 18, 24, 30, 36

5 and 6 both have 30 in common so that's the new denominator for all 3 of the terms.

What you do to the bottom you must do to the top.

Since you multiply 5 by 6 to get 30, you must multiply 2 and 4 by 6 as well.

Since you multiply 6 by 5 to get 30, then multiply 5 by 5 as well.

The new equation is:

$\frac{12}{30}$ + $\frac{25}{30}$ + $\frac{24}{30}$ =

Now add the numerators together

The solution is $\frac{61}{30}$ . Now simplify. 61 is prime, so you cannot change the fraction How many times does 30 go into 61? Two times. This gives us 2 $\frac{1}{30}$ .