(x+8)- (2x+7)
I got
-1x -1
but the correct answer is
-1x + 1
Why is it addition and not subtraction??
2006-09-05 03:41:58 · 11 answers · asked by this isnt my name. 1 in Science & Mathematics ➔ Mathematics
(x+8) - (2x+7)
Step 1: Remove the brackets
= x + 8 - 2x - 7
remember: if you have a minus in front of
the bracket all the signs inside the bracket change to the opposite sign. e.g. + changes to -.
that's why you get - 7 and not +7
= -1x +1.
not that hard hey?
2006-09-05 03:52:38 · answer #1 · answered by Op Vakansie 3 · 0⤊ 0⤋
That's easy:
(x+8)-(2x+7)=x+8-2x-7=-1x+1
2006-09-05 03:47:15 · answer #2 · answered by Razvan 2 · 0⤊ 0⤋
Because 7 is subtracted from 8 and 8-7= +1 not -1
2006-09-05 04:15:11 · answer #3 · answered by shrinjaykhandel 2 · 0⤊ 0⤋
the minus sign applies to everything within the brakets. You are not just subtracting 2x, you are subtracting (2x + 7), which is the same as subtracting 2x; then subtracting 7.
so, -(2x+7)= -2x -7
and your formula works out to:
(x+8) - (2x+7) =
x + 8 - 2x - 7 =
x -2x +8 - 7 =
-x + 1
2006-09-05 03:49:38 · answer #4 · answered by robcraine 4 · 0⤊ 0⤋
assumption
(x + 8) - (2x + 7)
x + 8 - 2x - 7
-x + 1
2006-09-05 09:08:59 · answer #5 · answered by SAMUEL D 7 · 0⤊ 0⤋
(x + 8) - (2x + 7)
= x + 8 - 2x - 7
= -x + 1
2006-09-05 03:47:38 · answer #6 · answered by Joe 4 · 0⤊ 0⤋
x+8-(2x+7)
= x+8 -2x -7
=(x-2x)+8-7
= -x +1
2006-09-05 04:00:02 · answer #7 · answered by Mein Hoon Na 7 · 0⤊ 0⤋
Where did you get -1x +1 from? I'd question it! I agree with the -1x-1 that you found originally. Ask your teacher for verification though.
2006-09-05 03:52:28 · answer #8 · answered by when's my next vacation??? 4 · 0⤊ 0⤋
You may have simply made a mistake.
when you get rid of brackets you get
x+8-2x-7
x-2x+8-7
-x+1
2006-09-05 03:48:18 · answer #9 · answered by konrad 2 · 0⤊ 0⤋
8 minus 7 equals 1, not negative 1.
Everything else was performed correctly
2006-09-05 05:03:25 · answer #10 · answered by Anonymous · 0⤊ 0⤋