Question

To solve the following simultaneous equations by Cramer's rule, find the values of D_x and D_y.

3x + 5y = 26

x + 5y = 22

Answer 1

3x + 5y = 26

x + 5y = 22

By Cramer's rule

D_x = `|(26, 5),(22, 5)|` 

= 26 × 5 – 22 × 5

= 130 – 110

= 20

D_y = `|(3, 26),(1, 22)|` 

= 3 × 22 – 1 × 26

= 66 – 26

= 40

∴ D_x = 20 and D_y = 40