16. Use the quadratic formula to solve the equation.
〖5x〗^2 - 47x = 156
18. What are the solutions to the equation x2 – 4x = -1?
19. Graph the set of points. Which model is most appropriate for the set of numbers?
(1,3), (0,0), (-3,3), (-1,-1), (-2,0)
3 answers
Please answer
actually just answer 18 and 19
#18
x^2-4x+1 = 0
x = (4±√20)/2 = 2±√5
#19
Hmmm. You don't say what models you have been using. Arranging the points from left to right, we have
x y
------
-3 3
-2 0
-1 -1
0 0
1 3
The symmetry makes me want to try a quadratic with vertex at (-1,-1)
y = (x+1)^2 - 1
x^2-4x+1 = 0
x = (4±√20)/2 = 2±√5
#19
Hmmm. You don't say what models you have been using. Arranging the points from left to right, we have
x y
------
-3 3
-2 0
-1 -1
0 0
1 3
The symmetry makes me want to try a quadratic with vertex at (-1,-1)
y = (x+1)^2 - 1