Answer:
Solution : (15, - 11)
Step-by-step explanation:
We want to solve this problem using a matrix, so it would be wise to apply Gaussian elimination. Doing so we can start by writing out the matrix of the coefficients, and the solutions ( - 5 and - 2 ) --- ( 1 )

Now let's begin by canceling the leading coefficient in each row, reaching row echelon form, as we desire --- ( 2 )
Row Echelon Form :

Step # 1 : Swap the first and second matrix rows,

Step # 2 : Cancel leading coefficient in row 2 through
,

Now we can continue canceling the leading coefficient in each row, and finally reach the following matrix.

As you can see our solution is x = 15, y = - 11 or (15, - 11).
Answer:
23
Step-by-step explanation:
Basically I did it backwards & opposites:
-28 divided by -7 = 4
4 + 19 = 23
I checked btw and it worked.
Answer:
Malcolm would fill 8 bags of rice.
Step-by-step explanation:
The size of the container of rice = 5
pounds =
pounds.
Each bag of rice has a capacity of
pounds.
The number of bags of rice that Malcolm fills = 
=
÷ 
=
x 
= 
= 8
Therefore, Malcolm would be able to fill 8 bags of rice.
Answer:
52 Sides
Step-by-step explanation:
Octagons have 8 sides so 3 x 8 = 24
Pentagons have 5 sides so 4 x 5 = 20
Trapezoids have 4 sides so 2 x 4 = 8
Add it all up and it equals 52 sides in total