Remark
There are occasions where this is very handy to know. Use FOIL.
Solve
F: (First): x*y = xy
O: (Outside): x *(-9) = - 9x
I:(Inside): (-7)*y = - 7y
L:(Last): (-7)*(-9) = 63
Add the terms together
xy - 9x - 7y + 63 <<<< Answer
Answer:
2,7
Step-by-step explanation:
y=65x
x represents the # of hours
128
