Question

Solve the following system.
y = x + 3
3x + y = 19

Answer 1

6.5

Answer 2

You can use Matrices as Before :)

Answer 3

Arrange the first eq first

Answer 4

what then ?

Answer 5

@uri reply ?

Answer 6

y = x + 3
x+y=-3

Answer 7

ok done then ?

Answer 8

x+y=-3
3x+y=19(mutiply by -1)

x+y=-3
3x-y=19
=======
4x=16
x=16/4
x=4

We have value of x now find y

Answer 9

is it -7 @uri

Answer 10

or 7 @uri

Answer 11

Another way you could have done it is to solve both equations for a single variable (for example y):
Thus:

y = x + 3
and
y = 19 - 3x

Next set the y variables equal to each other by placing one on one side of the equal sign and the other on the other as such:
x + 3 = 19 - 3x

Next you want to group like terms, so group the x's together on one side and the numbers on the other:
x + 3 = 19 - 3x
x + 3x + 3 = 19 -3x + 3x
x + 3x + 3 - 3 = 19 - 3
x + 3x = 19 - 3


Simplify:
4x = 16
x =16/4 = 4

To solve for why plug the value we just calculated for x into one of the original equations:

y = x + 3 --> y = 4 + 3 = 7

To double check,use the other equation:

3x + y = 19

3*4 + y = 19
12 + y = 19
Re-arrange
y = 19-12
y = 7
Bam!

Answer 12

I did it right,Did not I?

Answer 13

Put the value of x in original eq no.2

3x + y =19
3(4) +y =19
12+y=19
y=19-12
y=7

Answer 14

@uri Yes your analysis is completely right

Answer 15

:3