Answer:
A) y = 3(x -3)^2 -46
B) (3, -46)
C) look at the y-coordinate of the vertex
Step-by-step explanation:
A) Factor the leading coefficient from the variable terms.
y = 3(x^2 -6x) -19
Inside parentheses, add the square of half the x-coefficient. Outside, subtract the same value.
y = 3(x^2 -6x +9) -19 -3(9)
y = 3(x -3)^2 -46
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B) Compared to the vertex form, ...
y = a(x -h)^2 +k
we find a=3, (h, k) = (3, -46).
The vertex is (3, -46).
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C) The vertex is an extreme value (as is any vertex). The sign of the leading coefficient tells you whether the parabola opens upward (+) or downward (-). This parabola opens upward, so the vertex is a minimum.
If the leading coefficient is positive, the y-coordinate of the vertex is a minimum. If the leading coefficient is negative, the y-coordinate of the vertex is a maximum.
Answer:
y = 3x - 7
Step-by-step explanation:
Slope-intercept form:
y = mx + b
Where:
y is the y value.
m is the slope.
x is the x value.
And b is the y-intercept.
First, you want to find your slope. To do this, you can either use the slope formula to find the slope, or just count on the picture:
m = rise/run
m = 3/1
m = 3
With the slope formula, you first need to choose two points.
I chose:
(2, -1) and (3, 2)
Slope formula:
m = (y2 - y1) / (x2 - x1) {It doesn't matter which point you choose to be x2 and x1, just be consistent when you plug it into the formula}
m = (2 - (-1)) / (3 - 2)
m = 3/1
m = 3
Now that you have your slope, all you need is your y-intercept. To find your y-intercept, you can either look at the graph (again) to see where the line intersects with the y-axis, or you can solve it algebraically:
y-int = -7
To solve algebraically, choose a random point on the line and plug it into what you have for your equation so far and then solve for b.
I chose:
(2, -1)
y = 3x + b
-1 = 3(2) + b
-1 = 6 + b
-1 - 6 = b
b = -7
Now you have your final answer:
y = 3x - 7
Answer:
Step-by-step explanation:
2x + 4 = 6x - 10
Minus 2x on both sides
4 = 4x - 10
Add 10 on both sides
14 = 4x
Divide by 4 on both sides
14/4 = x
x = 14/4
Simplify fraction
x = 7/2 or x = 3 1/2
