
Vivian L. answered 03/10/14
Tutor
3
(1)
Microsoft Word/Excel/Outlook, essay composition, math; I LOVE TO TEACH
Hi Celsey;
x(x+2)=7920
Distribute the x...
x2+2x=7920
x2+2x-7920=0
For the FOIL...
FIRST must be (x)(x)=x2
OUTER and INNER must add-up to 2x.
LAST must be (90)(88) or (88)(90)...
(x+90)(x-88)=0
Either or both parenthetical equation(s) must equal zero...
x+90=0....................x-88=0
x=-90.......................x=88
room number cannot be negative. Second answer is only answer.
Room numbers are 88 and (x+2), 90.
Steve S.
03/11/14