1. 5x-2y= 10 X+y=5 2. -5x+1/4=-3×+12

itu jawabannya.. nomer 2 maaf kalo salah

5x - 2y = 10
x + y = 5
persamaan ke 2 dikali 5

5x - 2y = 10
5x + 5y = 25
_________-
3y = -15
y = -5

sub ----->
5x - 2y = 10
5x + 10 =10
5x = 0
x = 0
j

-5x + 1/4 =-3× + 12
-5x + 3x = 12 - 1/4
-2x = 47/4
x = -47/8

semoga membantu...
rh