Explanation:
Step 1 : 0.5x + y = 1.5
0.8x - 0.2y =6
Step 2 : y = 1.5 - 0.5x
0.8x - 0.2 ( 1.5 - 0.5x ) = 6
Step 3 : y = 1.5 - 0.5x
0.8x - 0.3 + 0.1x = 6
Step 4 : y = 1.5 - 0.5x
0.9x = 6.3
Step 5 : y = 1.5 - 0.5* 7
x = 7 ( put 7 into the x value above )
Ans: y = -2
x = 7
You can ask me if you don't understand any step^^