How would you solve 2x plus 5y equals -1 and x plus 2y equals 0?

Answer 1

A system?

2X + 5Y = - 1

- 2(X + 2Y = 0)

use multiplicative elimination; shown above

2X + 5Y = - 1

- 2X + - 4Y = 0

-----------------------add

Y = - 1

----------------now find X, bottom original ( X + 2Y = 0 ) equation will do

X + 2(- 1) = 0

X - 2 = 0

X = 2

----------------check in both original equations

2(2) + 5(- 1) = - 1

4 - 5 = - 1

- 1 = - 1

----------------top checks

(2) + 2(- 1) = 0

2 - 2 = 0

0 = 0

--------------both check and this system is consistent, (2, - 1) is the answer set