Answer:
x = -2 ± sqrt(5)
Step-by-step explanation:
x^2 + 4x – 1= 0
Add 1 to each side
x^2 + 4x – 1+1= 0+1
x^2 +4x = 1
Take the coefficient of x
4
Divide by 2
4/2 =2
Square it
2^2=4
Add it to each side
x^2 +4x+4=1+4
(x+2)^2 = 5
Take the square root of each side
sqrt((x+2)^2 )=± sqrt(5)
x+2 = ± sqrt(5)
Subtract 2 from each side
x+2-2 = -2 ± sqrt(5)
x = -2 ± sqrt(5)
a vertical axis, I assume it means a vertical axis of symmetry, thus it'd be a vertical parabola, like the one in the picture below.
![\bf ~~~~~~\textit{parabola vertex form} \\\\ \begin{array}{llll} y=a(x- h)^2+ k\qquad \qquad \leftarrow vertical\\\\ x=a(y- k)^2+ h \end{array} \qquad\qquad vertex~~(\stackrel{}{ h},\stackrel{}{ k}) \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ \begin{cases} h=0\\ k=0 \end{cases}\implies y=a(x-0)^2+0 \\\\\\ \textit{we also know that } \begin{cases} x=-2\\ y=3 \end{cases}\implies 3=a(-2-0)^2+0\implies 3=4a \\\\\\ \cfrac{3}{4}=a~\hspace{10em}y=\cfrac{3}{4}(x-0)^2+0\implies \boxed{y=\cfrac{3}{4}x^2}](https://tex.z-dn.net/?f=%5Cbf%20~~~~~~%5Ctextit%7Bparabola%20vertex%20form%7D%20%5C%5C%5C%5C%20%5Cbegin%7Barray%7D%7Bllll%7D%20y%3Da%28x-%20h%29%5E2%2B%20k%5Cqquad%20%5Cqquad%20%5Cleftarrow%20vertical%5C%5C%5C%5C%20x%3Da%28y-%20k%29%5E2%2B%20h%20%5Cend%7Barray%7D%20%5Cqquad%5Cqquad%20vertex~~%28%5Cstackrel%7B%7D%7B%20h%7D%2C%5Cstackrel%7B%7D%7B%20k%7D%29%20%5C%5C%5C%5C%5B-0.35em%5D%20%5Crule%7B34em%7D%7B0.25pt%7D%5C%5C%5C%5C%20%5Cbegin%7Bcases%7D%20h%3D0%5C%5C%20k%3D0%20%5Cend%7Bcases%7D%5Cimplies%20y%3Da%28x-0%29%5E2%2B0%20%5C%5C%5C%5C%5C%5C%20%5Ctextit%7Bwe%20also%20know%20that%20%7D%20%5Cbegin%7Bcases%7D%20x%3D-2%5C%5C%20y%3D3%20%5Cend%7Bcases%7D%5Cimplies%203%3Da%28-2-0%29%5E2%2B0%5Cimplies%203%3D4a%20%5C%5C%5C%5C%5C%5C%20%5Ccfrac%7B3%7D%7B4%7D%3Da~%5Chspace%7B10em%7Dy%3D%5Ccfrac%7B3%7D%7B4%7D%28x-0%29%5E2%2B0%5Cimplies%20%5Cboxed%7By%3D%5Ccfrac%7B3%7D%7B4%7Dx%5E2%7D)
The answer is 41% hope this helps
Answer:
7 . 4 + 6 - 12 : 4 = 31
Step-by-step explanation:
* To solve this problem lets revise the order of operations in
mathematics
- The operations are:
# Addition
# Subtraction
# Multiplication
# Division
# Exponentiation
# Grouping ⇒ Parenthesis or brackets
- The order of these operations is:
# Parenthesis
# Exponents
# Multiplication and Division which comes first from left to right
# Addition and Subtraction which comes first from left to right
- There is a word made from the first letter of each operation
PEMDAS to remember the order of operations
* Lets solve the problem
∵ 7 . 4 + 6 - 12 : 4
∵ The (.) means multiply the numbers
∵ The symbol (:) means divided the numbers
∴ At first multiply 7 by 4 and divide 12 by 4
∴ (7 × 4) + 6 - (12 ÷ 4)
∴ 28 + 6 - 3
∵ Addition comes before subtraction from the left
∴ (28 + 6) - 3
∴ 34 - 3 = 31
∴ 7 . 4 + 6 - 12 : 4 = 31
