39.21x+2.65=42.03x
can anyone explain to me how to solve this decimal equation and if you can please try to put in 8th grade terms. oh and if you can do you mind solving this one for me too? -7x+32=-21
thankyou!
The idea is to
1. Get rid of the term which DOES NOT contain x on the LEFT by
adding its opposite to both sides:
39.21x + 2.65 = 42.03x
Get rid of the + 2.65 by adding -2.65 to both sides
39.21x + 2.65 = 42.03x
- 2.65 = - 2.65
-----------------------------
39.21x = 42.03x - 2.65
Then
2. Get rid of the term which DOES contain x on the RIGHT by
adding its opposite to both sides:
39.21x = 42.03x - 2.65
Get rid of the 42.03x by adding -42.03x to both sides
39.21x = 42.03x - 2.65
-42.03x = -42.03x
--------------------------
-2.82x = -2.65
3. Get rid of the coefficient of x, which is -2.82,
by dividing both sides by -2.82.
-2.82x -2.65
-------- = -------
-2.82 -2.82
Cancel the -2.82's on the left
-2.82x -2.65
-------- = -------
-2.82 -2.82
-2.65
x = -------
-2.82
Divide the numbers on the right
x = .9397163121
You can round that however you are told, either as
.94, .940, .9397, etc.
----------------------------------------
-7x + 32 = -21
Again the idea is to
1. Get rid of the term which DOES NOT contain x on the
LEFT by adding its opposite to both sides:
-7x + 32 = -21
Get rid of the +32 by adding -32 to both sides
-7x + 32 = -21
- 32 = -32
--------------
-7x = -53
There are no terms containing x on the right, so this is
an easier problem and we can skip step 2.
3. Get rid of the coefficient of x, which is -7, by dividing
both sides by -7.
-7x -53
----- = -----
-7 -7
Cancel the -7's on the left
-7x -53
----- = -----
-7 -7
-53
x = ---
-7
Divide the numbers on the right (cancel the negative signs)
53
x = ----
7
You can leave it as 53/7.
Edwin
AnlytcPhil@aol.com
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