9x+7=5x-3
help me with the steps and show me how you got the answer...thanks and i'll give you 10 pts!
2007-08-01 10:55:31 · 3 answers · asked by lele 2 in Education & Reference ➔ Homework Help
9x +7=5x-3 (minus 5x both sides)
4x +7=-3 (minus 7 both sides
4x=-10
x= -10/4
2007-08-01 11:00:30 · answer #1 · answered by happy.girl 5 · 0⤊ 0⤋
9x + 7 = 5x - 3
Collect x terms together (9x and 5x)
and also constant terms together (7 and -3)
9x - 5x = - 3 -7
(this is the same as subtracting
5x from both sides, and also 7 from both sides)
4x = - 10
Divide both sides by 4 to get
x = - 10/4 or - 5/2
The first answer is right, but needs to be
reduced to lowest terms,
either - 5/2 or
- 2 1/2
- 2.5
The second answer has an error because
when you "subtract" 7 from both sides
you get -10 not 4
To check your work, plug -2.5 back in for x
in the original problem
9(-2.5) + 7 = 5 (-2.5) - 3
7 - 22.5 = - 12.5 - 3
- 15.5 = -15.5
This appears to be correct
If you check your work this way
you can always be sure of your answer
[For example, if you tried to check x = -1
you would get
-9 + 7 = -5 -3
- 2 = -8
so you would know something is wrong with that answer]
2007-08-01 18:29:01 · answer #2 · answered by Nghiem E 4 · 1⤊ 0⤋
Subtract 5x from each side
4x+7= -3
Subtract 7 from each side
4x= -4
Divide each side by 4
x= -1
2007-08-01 18:00:38 · answer #3 · answered by Katharine G 2 · 0⤊ 0⤋