X is equal to 8. The work for that is on the attached picture.
The 18th month he will have to change both,
I hope this helped!
Answer:
Divide the 1st equation by 2
a + 2c = 19
Divide the 2nd equation by 3
a + c = 13.5
Subtract the 1st equation and the 2nd equation
c = 5.5
Substituting back into the 2nd equation will give:
a + 5.5 = 13.5
a = 8
Step-by-step explanation:
Doing (2x-5) first is what