Answer:
D. Multiply the second equation by 3. The solution is x = 12, y = 10
Step-by-step explanation:
Given:
x + 3y = 42 (first equation)
2x - y = 14 (second equation)
To solve by elimination, starting with elimination of the y-variable, multiply the second equation by 3 to get a third equation.
2x - y = 14 (2nd eqn.) × 3
6x - 3y = 42 (3rd equation)
Add the 3rd equation and the 1st equation together.
x + 3y = 42 (first equation)
6x - 3y = 42 (3rd equation)
7x = 84
7x/7 = 84/7
x = 12
To find y, substitute x = 12 in the first equation
x + 3y = 42 (first equation)
12 + 3y = 42
12 + 3y - 12 = 42 - 12
3y = 30
3y/3 = 30/3
y = 10
Solution is x = 12, y = 10
