Equation of a line:

m = gradient: The difference between two y points and two x points.

c = y-intercept: Where the line crosses the y-axis (x=0)
You have:

so you are missing the m and the c.
To calculate m find two y coordinates -you have (12,
<u>7</u>) and (0, <u>
1</u>)- and subtract them. Then divide this by the subtracted values of the x coordinates -you have (<u>
12</u>, 7) and (<u>
0</u>, 1)- This gives:



To calculate the c, you just see where the line crosses the y-axis. Because you have the point (0, 1), you know that when x=0, y=1. Because x=0 is on the y-axis, you can tell that the line passes through y=1. This makes your c = 1:

When you plug these values into the equation you get your answer:
Answer:
x = -16
Step-by-step explanation:
C=x+9, c+x=99, c=99-x
So we have two equations equal to c, c=x+9 and c=99-x, since c=c:
x+9=99-x
2x+9=99
2x=90
x=45, and since c=x+9, c=54
So Charlie weighs 54 kg and his brother weighs 45 kg.
Answer:
The scale factor is the ratio of the length of a side of one figure to the length of the corresponding side of the other figure.
Step-by-step explanation:
Your answer is A. If we find the slope of the line and draw it out farther, we can see that the points 4,7,10, and 13 would fall on that line.