The sum means addition.
Add the like terms together.
4x^3+2x^2-4x+3
+ 7x^3-4x^2+7x+8
4x^3 + 7x^3 = 11x^3
2x^2 + -4x^2 = -2x^2
-4x +7x = 3x
3 +8 = 11
The answer is : 11x^3 - 2x^2 + 3x + 11
The <em>speed</em> intervals such that the mileage of the vehicle described is 20 miles per gallon or less are: v ∈ [10 mi/h, 20 mi/h] ∪ [50 mi/h, 75 mi/h]
<h3>How to determine the range of speed associate to desired gas mileages</h3>
In this question we have a <em>quadratic</em> function of the <em>gas</em> mileage (g), in miles per gallon, in terms of the <em>vehicle</em> speed (v), in miles per hour. Based on the information given in the statement we must solve for v the following <em>quadratic</em> function:
g = 10 + 0.7 · v - 0.01 · v² (1)
An effective approach consists in using a <em>graphing</em> tool, in which a <em>horizontal</em> line (g = 20) is applied on the <em>maximum desired</em> mileage such that we can determine the <em>speed</em> intervals. The <em>speed</em> intervals such that the mileage of the vehicle is 20 miles per gallon or less are: v ∈ [10 mi/h, 20 mi/h] ∪ [50 mi/h, 75 mi/h].
To learn more on quadratic functions: brainly.com/question/5975436
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Answer:girl use google
Step-by-step explanation:what
The answer to the question is B
We can divide each digit by 7. So 56/7=8 and 21/7=3
so.... 8:3