This question seems oddly worded but i guess if you collected $128 in donations then you collected $128 for charity
Plug 4x=9 in for y:
10x=18-2(4x+9)
10x=18-8x-18
10x=-8x
18x=0
x=0
now plug 0 in for x:
y=4(0)+9
y=9
to check, plug x and y back into one of the equations to make sure they are right:
10(0)=18-2(9)
0=18-2*9
0=18-18
0=0
Wooo nada I just want ya to be a good friend to