Question

Solve the system: x + 5y = -15 -2x -10y = 30

Answer 1

Hello !

This is a simple linear system and you can solve it with the method of comparation, see the resolution below in the practice.

Linear system.

x + 5y = -5

-2x - 10y = 30

Isolate the y in the first equation.

x + 5y = -5

5y = -5 - x

y = (-5 - x)/5

Isolate the y in the second equation.

-2x - 10y = 30

-10y = 30 + 2x

y = (30 + 2x)/(-10)

Now, you make the comparation and find the solution for (x).

(-5 - x)/5 = (30 + 2x)/(-10)

5(30 + 2x) = -10(-5 - x)

150 + 10x = 50 + 10x

10x - 10x = 50 - 150

0 = -100

Well, here we have that this equality is false. Because we know that 0 isn't equal -100. Therefore, with just this information we can have the conclusion that this linear system hasn't solution.

I hope I have collaborated !