8th Grade Mental Math
17 * 3
51
There are _______ quadrants on a coordinate plane
4
What is slope?
The rate of change.
Point A(4, 2) is reflected over the y axis. What is the coordinate of the image?
A'(-4, 2)
26+98
124
What is the x value of the y-intercepts coordinates?
0. (0, y)
Conner eats 12 hotdogs in 6 mins. Brenda eats 8 hotdogs in 3 minutes.
If graphed, which person would have the steeper slope?
Brenda's slope would be steeper.
Point D(1, 3) is rotated 180 degrees around (0, 0). What is the coordinate of the image?
D'(-1, -3)
2(3+5)
16
What signs do the coordinates in Quadrant IV have?
(+, -)
If a line is decreasing then it's slope is __________
Negative
y = 1/2x + 4: What is the slope?
1/2
8(4-9)+12
-28
What is the point slope formula?
y2 - y1 Divided by x2 - x1
How can you tell if a slope is positive or negative just by looking at the graph?
Line going up and to the right is positive, line going down and to the right is negative.
y = x - 3: What is the y-intercept?
-3
(7-4)+(8-2)
9
What is the formula for slope-intercept form?
y = mx + b
When Timmy was first born, he weighed 8.5 pounds. Every month he gained 1.5 pounds. Write an equation in slope intercept form that represents this situation.
y = 1.5x + 8.5
What would the line x=5 look like?
A vertical line at 5 on the x axis.