Question

For which system of equations would elimination be the simplest technique to choose?
A. y = 2x and x + 3y = 5
B. 4x + 3y = 6 and 3y = 5
C. x + y = 7 and x - y = 12
D. 3x - 2y = 8 and 4x - 5y = 20

Answer 1

Hint: look for a pair of equations containing two equal yet opposite variables.

Answer 2

2nd Hint:
In the two equations below, the opposite variables + a and -a allow for simple variable elimination because +a - a = 0:

x + a = 4
x - a = 2

Answer 3

3rd Hint:

7x + y = 2
7x - y = 3

The two equations above contain opposite variables +y and - y. Since + y - y = 0, this allows for simple elimination.