SOLUTION: Solve using Cramer's Rule. -2x + 3y = 16 4x = -3y + 40

Algebra.Com
Question 47337: Solve using Cramer's Rule.
-2x + 3y = 16
4x = -3y + 40

Answer by longjonsilver(2297)   (Show Source): You can put this solution on YOUR website!
-2x + 3y = 16
4x = -3y + 40

becomes
-2x + 3y = 16
4x + 3y = 40

in matrix form, we have:



And its determinant is (-2)(3) - (4)(3)
D = -6 - 12
D = -18

Now re-write the matrix as:

to calculate the x-version Determinant, Dx --> (16)(3) - (40)(3)
Dx = 48 - 120
Dx = - 72

Now re-write the matrix as:

to calculate the y-version Determinant, Dy --> (-2)(40) - (16)(4)
Dy = -80 - 64
Dy = -144

Now, x = Dx/D
x = -72/-18
x = 4
and y = Dy/D
y = -144/-18
y = 8

check:
-2x + 3y = 16
-2(4) + 3(8)
-8 + 24
16 --> correct

4x + 3y = 40
4(4) + 3(8)
16 + 24
40 --> correct

Look at my Lesson on a 3x3 Matrix using Cramer's Rule

jon.

RELATED QUESTIONS

4x+3y=100 2x+4y=120 solve using simultaneous equation with cramer... (answered by lynnlo)
Solve using Cramer’s rule 3x-y+2z=13, 2x+y-z=3, x+3y-5z=-8 (answered by Edwin McCravy)
Solve the following system of equations by using Cramer's Rule: "-2x+3y-z=1," x+2y-z=4,... (answered by Alan3354)
Solve the following system of equations using cramer`s rule 2x + y - z= 5 3x - 2y +... (answered by Edwin McCravy)
Solve the system with three variables by Cramer's Rule. -2xy 3z = 3 2x - 3y + z =... (answered by ikleyn)
Solve the simultaneous equation using matrix and cramer rule 2x+3y-z=1 3x+5y+2z=8... (answered by Fombitz)
solve using cramers rule 2x+3y=4... (answered by BlackMamba2994)
Solve the system with three variables by Cramer's Rule. -2x -y -3z = 3 2x -3y +z = (answered by ikleyn)
solve using cramer rule :- 3x+2y+4z=19 2x-y+z=3 6x+7y-z=7 x-y+2z=1 x+y+z=2 2x-y+z=5... (answered by ikleyn)