Since it's a one-variable equation, it has only one solution:
25 - 4x = 15 - 3x + 10 - x
25 - 4x + x = 15 - 3x + 10
25 - 3x = 15 - 3x + 10
- 3x = 15 - 3x + 10 - 25
- 3x = 15 - 3x - 15
- 3x + 3x = 15 - 15
0 = 15 - 15
0 = 0
Hope it helped,
BioTeacher101
to find the slope for the first one, use the formula 
(It's the slope formula)
so... 
then plug in... 
this line has a slope of 0
As for the miles problem, to find mph, the miles have to be at 1.
so... 
therefore, he drove 60.5 mph
The value of 9 is 9,000 it’s in the Thousands place
Answer:
a) 21
Step-by-step explanation:
If the columns are labeled a, b, c, d left to right, it appears that we have ...

The value of M is 21.
_____
Questions like this require that you try different combinations of operations on the numbers shown to see if you can find a relationship. Here, the left column is a perfect square, so that is a clue. The difference of the numbers in the middle columns is a factor of the number in the right column -- another clue. It takes a certain amount of creative thought and familiarity with arithmetic facts. There is no "step-by-step" for a problem like this.
First, find slope of point A and B using slope formula:
<u>y2-y1</u> = <u>7-0 </u>= <u>-7</u>
x2-x1 3-8 5
Next, use the point-slope formula to find the equation (pick either point A or B to substitute into this equation; the answer will be the same either way):
y-y1=m(x-x1)
y-7=<u>-7</u>(x-3) (I used point B here)
5
y=<u>-7x</u> +<u>56</u> so the y-intercept is <u>56</u>. Hurray! Part 1 down!
<span> 5 5 5
Now to answer part 2. Since AB ll CD, they have the same slope: <u>-7</u>
5
Therefore, you can use the handy point-slope equation to calculate the equation of line CD. (Remember you only need one of the points to use this equation if you already have the slope.) Since the only point given is D(5,5), we'll use that one:
</span>y-y1=m(x-x1)
y-5=<u>-7</u>(x-5)
<span> 5
</span>y=<u>-7x</u> + 12 Yay! That's the answer to part 2; the equation of line CD
<span> 5</span>