Her conclusion is not valid because she watered the area containing Brand B twice as much as the Brand A area.
Hun your over thinking this. It has the word substitute right in it which mean substitution property
1) 9x+4y=11
3x-10y=-2 -----> 9x-30y=-6
9x+4y=11
-(9x-30y=-6)
------------------
34y=17
y=1/2
9x+4(1/2)=11
9x=9
x=1
2) 4x+3y=21 -----> 8x+6y=42
5x+2y=21 -----> 15x+6y=63
8x+6y=42
-(15x+6y=63)
-7x=-21
x=3
4(3)+3y=21
3y=9
y=3
50x8=400
4x8=32
___
432
Break apart 54 and it becomes 50x8 and 4x8.
unlikely roughtly 40% have computers you cant make up for that other 10 percent
