tolong donk jwab no 20-24

no 22. 3x+4y = 7. dikali 3
-2x+3y = -16. dikali 4
jadi,
9x + 12y = 21
-12x + 12y = -72
------------------------ dikurangi
-3 x= -51
x = 17

3x + 4y = 7
3(17) + 4y = 7
51 + 4y = 7
4y = 7-51
y = -11


dit : 2x-7y = ?
2(17) - 7(-11)
34 +77
= 108