Question

Using Cramer’s Rule, what is the value of x in the system of linear equations below?

5x - 4 = 3y
2x +32 = 4y

a. 1/12
b. 2/3
c. 8
d. 12

Answer 1

x = 8 is the answer

Explanation:

In order to find the solution of Equations using Cramer's rule

we shall find matrices

D=
`\left[\begin{array}{ccc}5&-3\\1&-2\end{array}\right]`=

`D_(1) = \left[\begin{array}{ccc}4&-3\\-16&-2\end{array}\right]`

l D l = Determinant formed by coefficient of variables

Here l D l = 5X(-2) - 1X(-3)= -10+3 = -7

l D1 l = Determinant formed by replacing first column In D by numbers on the right side of the equations

Here l D1 l = 4X(-2)- (-16)X(-3)= -8-48 = -56

here x is given by
`(l D1 l)/(l D l)`

x =
`(-56)/(-7)`

x = 8