solve by the elmination method

0.3x-0.2y=4
0.4x+0.3y=49/23

1st one by 30 ----> 9x - 6y = 120

2nd by 20 -------> 8x +6y = 980/23
add them
17x = 3740/23
x = 220/23

back into 8x + 6y = 980/23
1760/23 + 6y = 980/23
6y = -780/23
y = -130/23