Answer:
The solution is (-2,4)
Step-by-step explanation:
We'll solve the system
2x+5y=16
-5x-2y=2
using elimination by addition and subtraction.
Let's eliminate x first. To do this, multiply the first equation by 5 and multiply the second equation by 2. We get:
10x + 25y = 80
-10x - 4y = 4
----------------------
21y = 84. Thus, y = 84/21 = 4.
Subbing 4 for y in the second equation, we get
-5x -2(4) = 2, or
-8 - 2 = 5x, or
-10 = 5x. Thus, x = -10/5 = -2.
The solution is (-2,4)
