Question

solve by cramer rule x+18=2y ;y=2x-9​

Answer 1

Answer:x=12 & y=15

Step-by-step explanation: Attached hereby is the step-by-step explanation.

Answer 2

Step-by-step explanation:

Given that: x+18=2y ;y=2x-9

To find : Solution using Cramer's Rule

Method:

Write the equation in standard form

$x - 2y = - 18 \\ 2x - y = 9$

Make matrix of coefficient of x and y and constant terms

$\left[\begin{array}{cc}1&-2\\2&-1\\\end{array}\right]\left[\begin{array}{c}x\\y\\\end{array}\right]=\left[\begin{array}{c}-18\\9\\\end{array}\right]$

Now to find the value of x,put the constant matrix at the place of coefficient of x,find determinant of it,find determinant of coefficient matrix and divide.

$x=\frac{\left|\begin{array}{cc}-18&-2\\9&-1\\\end{array}\right|}{\left|\begin{array}{cc}1&-2\\2&-1\\\end{array}\right|}\\\\x=\frac{36}{3}\\\\x=12$

$y=\frac{\left|\begin{array}{cc}1&-18\\2&9\\\end{array}\right|}{\left|\begin{array}{cc}1&-2\\2&-1\\\end{array}\right|}\\\\y=\frac{45}{3}\\\\y=15$

Thus,value of x= 12 and y=15.

Hope it helps you