Answer:
The turning point of the graph is at (3,-16)
Step-by-step explanation:
The general equation of curve is given as:
y = x² + ax + b
The two point for which the equation satisfies is (0,-7) and (7,0).
Substitute (0,-7) in the general equation:
y = x² + ax + b
-7 = 0² + a(0) + b
b = -7
Substitute (7,0) in the general equation:
y = x² + ax + b
0 = 7² + 7a + b
Where b = -7
0 = 49 + 7a - 7
0 = 42 + 7a
a = -6
The equation of the curve is:
a = -6 and b = -7
y = x² + ax + b
y = x² - 6x - 7
Graph of the equation is attached below.
We can see that the the turning point of the graph is at (3,-16)
A)
The question tells us that
y + z = 180
And
y=3x+20
z=x
So we put them in the first formula:
y + z = 180
(3x + 20) + x = 180
Add and get x to one side:
4x + 20 = 180
4x + 20 - 20 = 180-20
4x = 160
Divide both sides by 4
x = 40
B)
Put x back in to equation to get size of each angle:
Y =3x +20
Y=3(40)+20
Y=120+20
Y=140
Z=x
Z=40
Verify: y+z=180
140+40=180
180=180
The answer is:
14.875
Hope this helps