x=ferns ; y=ivy
12x+8y=260
6x+15y=240
x=60 -(15/6)y
12(60+ (15/6)y + 8y = 260
x=60 -(15/6)y
720 - 30y + 8y = 260
x=60- (15/6)y
-30y +8y= 260-720 ==> -22y= -460
x=60 -(15/6)y
y= (-460)/(-22)= 20.9090909091
y=20.90
x=60 -(15/6)×20.90= 7.75
×(ferns)=7.75$
y(ivy)=20.90$