McGraw Hill Glencoe Algebra 2, 2012
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McGraw Hill Glencoe Algebra 2, 2012 View details
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Exercise 40 Page 210

The coefficient matrix is a matrix that contains only the coefficients of the system. Start by calculating |C|, the determinant of the coefficient matrix.

(2,6)

Practice makes perfect

We will use Cramer's Rule to solve the given system of equations and find the intersection point of the two given lines. 3x - 1y= 5x+2y=22 Let C be the coefficient matrix of the system. The coefficient matrix is a matrix that contains only the coefficients of the system. C= [ cc 3 & -1 5 & 2 ] If the determinant of the coefficient matrix, |C|, is different from zero, we can find the solution to our system, (x,y), by using determinants. x=| cc & -1 22 & 2 |/|C| and y= | cc 3 & 5 & 22 |/|C| Let's start by calculating |C|.

|C|=| l 3 & -1 5 & 2 |
â–¼
Calculate determinant

| la & b c & d |=ad-bc

|C|=3(2)-(-1)5
|C|=6-(-5)
|C|=11

We can now substitute 11 for |C| and calculate the value of x.

x=| l & -1 22 & 2 |/|C|
x=| l0 & -1 22 & 2 |/11
â–¼
Simplify right-hand side

| la & b c & d |=ad-bc

x=0(2)-(-1)22/11
x=0-(-1)22/11
x=0-(-22)/11
x=0+22/11
x=22/11
x=2

Finally, we will substitute 11 for |C| in the formula for y.

y=| l 3 & 5 & 22 |/|C|
y=| l3 & 0 5 & 22 |/11
â–¼
Simplify right-hand side

| la & b c & d |=ad-bc

y=3(22)-0(5)/11
y=66-0/11
y=66/11
y=6

The solution of the system, which is the point of intersection of the lines, is (2,6).