Answer:
Nice to hear that, congrats with practice 7.3
first off, let's notice the parabola is a vertical one, therefore the squared variable is the x, and the parabola is opening upwards, meaning the coefficient of x² is positive.
let's notice the vertex, or U-turn, is at (-2, 2)
![\bf ~~~~~~\textit{parabola vertex form} \\\\ \begin{array}{llll} \boxed{y=a(x- h)^2+ k}\\\\ x=a(y- k)^2+ h \end{array} \qquad\qquad vertex~~(\stackrel{-2}{ h},\stackrel{2}{ k}) \\\\\\ y=+1[x-(-2)]^2+2\implies y=(x+2)^2+2](https://tex.z-dn.net/?f=%20%5Cbf%20~~~~~~%5Ctextit%7Bparabola%20vertex%20form%7D%20%5C%5C%5C%5C%20%5Cbegin%7Barray%7D%7Bllll%7D%20%5Cboxed%7By%3Da%28x-%20h%29%5E2%2B%20k%7D%5C%5C%5C%5C%20x%3Da%28y-%20k%29%5E2%2B%20h%20%5Cend%7Barray%7D%20%5Cqquad%5Cqquad%20vertex~~%28%5Cstackrel%7B-2%7D%7B%20h%7D%2C%5Cstackrel%7B2%7D%7B%20k%7D%29%20%5C%5C%5C%5C%5C%5C%20y%3D%2B1%5Bx-%28-2%29%5D%5E2%2B2%5Cimplies%20y%3D%28x%2B2%29%5E2%2B2%20)
The answer is D. This is because all of the variables must be on one side so it can be factored.
8x + 7y = 39
4x - 14y = -68
(multiply each term in second equation by -2)
8x + 7y = 39
-8x + 28y = 136
(add both equations)
35y = 175
(divide both sides by 35)
y = 5
(substitute value of y in one of the equations)
8x + 7(5) = 39
8x + 35 = 39
8x = 4
x = 1/2
(x, y) = (1/2, 5)
Answer:
see explanation
Step-by-step explanation:
Since p(x) = x² + 2 , if x ≤ 4
For x = 4 then this is included in the inequality x ≤ 4
whereas x > 4 does not include x = 4 but values greater than 4
Thus to evaluate x = 4 use p(x) = x² + 2
