Ok so
parabola standard form is
y=ax^2+bx+c
if you have the points
(-2,18)
(0,4)
(4,24)
sub points to find a,b and c
(-2,18)
sub -2 for x and sub 18 for y
18=a(-2)^2+b(-2)+c
18=4a-2b+c
(0,4)
sub 0 for x, nice a, an b cancel
4=a(0)^2+b(0)+c
4=0+0+c
4=c
we can sub that back later
(4,24)
24=a(4)^2+b(4)+c
24=16a+4b+c
we have
18=4a-2b+c
c=4
24=16a+4b+c
sub 4 for c
18=4a-2b+4
24=16a+4b+4
minus 4 from both sides
14=4a-2b
20=16a+4b
simlify all equations
7=2a-b
5=4a+b
add to solve for 6a
12=6a+0b
12=6a
divide both sides by 6
2=a
sub back
7=2a-b
7=2(2)-b
7=4-b
-3=b
equation is
y=2x^2-3x+4
The solution is shown in the graph attached.
Explanation:
I am goind to teach you how to get that solution.
1) Restricctions: both x and y cannot be negative, i.e.
x ≥ 0 and y ≥ 0⇒ the solution is on the
first quadrant.2) Using the prices of the tickets, $ 8 for adults, and $ 6 for children, the linear equation for the
costs is: cost = 8x + 6y.3) Since the radio station is willing to spend a
maximum of $ 172 you have the final restriction:
⇒ 8x + 6y ≤ 172.4) Then the solutions that meet the three restrictions (x ≥0, y ≥ 0, and 8x + 6y ≤ 172) is found graphically by drawing the line 8 x + 6y = 172
5) To draw the line 8x + 6y = 172, use the axis intercepts:
x = 0 ⇒ y = 172/6 = 86/3 ⇒ point (0, 86/3)
y = 0 ⇒ x = 172/8 = 86/4 ⇒ point (86/4, 0)
6) Once you have the line you
shade the region that is between the line and the two axis. That region contain of the possible solutions.
40% of the apples are not right. Since only 3/5 are right, the that would leave 2/5 to not be right. Since 2/5=40/100, then the answer is 40%. That's just the eay I remember it, hope this helps