During the 2009-2010 season, inter milan of the Italian series A scored 82 points on 38 rounds. For each round of the game, the winning team would receive 3 points, while the losing team would get 0 points. But if the game ends up in a tie, each team would get 1 point. Inter Milan won 20 more rounds than they lost. Use a matrix to find how many of each type of shot they made

Inter milan had 24 wins, 10 draws and 4 losses.

Step-by-step explanation:

Let n₁ = number of wins, n₂ = number of draws and n₃ = number of number of losses. Let W = win points = 3, L = loss points = 0 and D = draw points = 1 Since we have our total number of points a 82, then

n₁W + n₂D + n₃L = 82

3n₁ + n₂ + 0n₃ = 82   (1)

Also, since there are 38 points in total, we have that

n₁ + n₂ + n₃ = 38    (2)

Also, we have 20 more win points than loss points. So,

n₁ = n₃ + 20

n₁ + 0n₂ - n₃ = 20 (3)

We have 3 equations. We now write them in matrix form below.

In the form AX = B, where A =  

Using cramer's rule, n₁ =

= 82((-1 × 1) - 0 × 1) - 1((38 × -1)- (20 × 1)) + 0((38 × 0) - 20 × 1) ÷ 3((-1 × 1) - 0 × 1) - 1((-1 × 1) - 1 × 1) + 0(1 × 0 + 1 × 1)

= (-82 + 58 + 0)/(-3 + 2 + 0)

=  -24/-1

= 24

n₂ =

= 3((38 × -1)- (20 × -1)) - 82((-1 × 1) - 1 × 1)  + 0(20 × 1 - (38 × 1) ) ÷ 3((-1 × 1) - 0 × 1) - 1((-1 × 1) - 1 × 1) + 0(1 × 0 + 1 × 1)

= (-174 + 164 + 0)/(-3 + 2 + 0)

=  -10/-1

= 10

n₃ =  

= 3((1 × 20)- (0 × 38)) - 1((1 × 20) - 1 × 38)  + 82(1 × 0 - (1 × 1) ) ÷ 3((-1 × 1) - 0 × 1) - 1((-1 × 1) - 1 × 1) + 0(1 × 0 + 1 × 1)

= (60 + 18 - 82)/(-3 + 2 + 0)

=  -4/-1

= 4

So, Inter milan had 24 wins, 10 draws and 4 losses.

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18