Answer:
{y | y ≥ -11 }
Step-by-step explanation:
To answer a question like this, it is often helpful to graph the function or to rewrite it to vertex form.
f(x) = 3x^2 +6x -8
f(x) = 3(x^2 +2x) -8 . . . . factor the leading coefficient from x terms
f(x) = 3(x^2 +2x +1) -8 -3(1) . . . . complete the square*
f(x) = 3(x +1)^2 -11
The form of this equation tells you that the graph is a parabola that opens upward. Its vertex is (-1, -11), so the minimum value is -11. The range is the vertical extent of the function values, so goes upward from -11:
y ≥ -11
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* Vertex form is ...
f(x) = a(x -h)^2 +k
where "a" is the vertical scale factor and (h, k) is the vertex. When "a" is positive, the parabola opens upward; when it is negative, the parabola opens downward.
The square is completed by adding the square of half the x-coefficient inside parentheses, and subtracting the equivalent amount outside parentheses. Here, we had 2x inside parentheses, so we added (2/2)^2 = 1 inside and -3(1) outside, because "a" was 3.
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Brainly provides tools for properly rendering math symbols. 2-11 is not the same as ≥-11.
Box of markers = $ B
Shoulder bag = Twice as much as the box of markers = $ 2B
Pen = Six less than the shoulder bag = $ (2B - 6)
Hence, the cost of pen is $ (2B - 6).
A. x = 7, y = 4, z = 3
How?
Just plug in the numbers.
7 + 4 + 3 = 14
11 + 3 = 14
14 = 14
Next.
4 + 3 = 7
Next.
3 = 3
<span>Step–1:Find a perfect square root as close to your number.
</span><span>Step–2: Divide your number by the square root.
</span><span>Step–3: Calculate the average of the result given in step 2 and the root.
Step-4: Simplify if needed. </span>
Assuming that the cost per minute is the same for both months and the plan fee is the same, you can use y=mx+b for this
y is the cost of the phone plan, x is the cost per minute and b is the start cost.
so 19.41=25x+b for the first month
and 45.65=380x+b for the second month
solve both for b you get:
19.41-25x=b and 45.65-380x=b. from this we get
19.41-25x=45.65-380x
solve for x
328x=26.24 and x=0.08
this means the cost per minute is 0.08c/min (answer A)
rewrite the equation to calculate b, and where this time, the x is the number of minutes talked.
y=0.08x+b and plug in one of the two months
45.65=0.08 * 380 + b
Solve for b and b is 15.25
so the final equation is
y=0.08x+15.25 (answer B)
