Step-by-step explanation:
The numerical expression is:
(36 + 14) / (2 * 5).
I have no idea what did he do
Answer:
X = 5
Step-by-step explanation:
Here is what I am picturing (not to scale)
A ----------------B-----------C
We are given the information of AB (which equals 3x + 1), BC (which equals 4x - 5), and AC (which equals 8x - 9).
With reference to the line, AB + BC = AC
So,
3x + 1 + 4x - 5 = 8x - 9
7x - 4 = 8x - 9
5 = x
I would assume Independent because pulling 1 marble doesn't cause you to pull a second one.
Linear equations are all solved the same way. Figure out the operations performed on the variable. Undo those in reverse order.
Here, the variable is
- divided by 2
- has -7 added.
In reverse order, we undo these operations by
- adding 7
- multiplying by 2.
Whatever we do to one side of an equation, we must also do to the other side. That is how the equal sign remains valid.
2 = m/2 -7
2 +7 = m/2 -7 +7 . . . . . add 7
9 = m/2 . . . . . . . . . . . . simplify
2*9 = 2*m/2 . . . . . . . . multiply by 2
18 = m . . . . . . . . . . . . . simplify. (You know that 2/2 = 1, and m*1 = m.)
The answer is m = 18.
_____
Check:
.. 2 = 18/2 -7
.. 2 = 9 -7 . . . . . . . true. The answer checks OK.
