Example elimination method

IKF

1. ELIMINATION METHOD.
Daniela Sánchez Rodríguez.
Mireya Genol Morales.
María Sánchez García.

2. The first thing we need to do is to multiply the first equation of the
system by the number of the first term in the second equation but
changing its sign. Then we need to solve the system as if we were doing
an addition. The last thing we need to do is to substitute the value of “y” in
any of the two equations in order to get the value of “x”.

3. Examples:
2x + y = 5
x - 3y = 6

-3x + 2y = 1
2x + 5y =12

4. Exercises:
2x - 3y = -5
-5x + 7y = 11

5x + 6y = 20 x + y = 2000
3x + 8y = 34 x + 10x + y + 15y = 2260



x - 5y = 8

-7x + 8y = 25
100 100

5. In a school there are 60 teachers spread over two
pavilions, A and B. 30% of A and 10% of B are men, making a
total of 10 teachers. How many teachers are there in each
pavilion?