Quadratic
y = ax^2 + bx + d
c (x) = ax^2 + bx + d
c (3) = a (3^2) + b (3) + d
c (3) = 9a + 3b + d = 15.50
c (7) = a (7^2 + b (7) + d
c (7) = 49a + 7b + d = 23.50
c (12) = a (12^2) + b (12) + d
c (12) = 144a + 12b + d = 56
solve using simultaneous equations... to get a b and d
use that to solve for x = 5
hope this helps?
First we need to found out how many pounds and luggage to small plane can carry, now that we know there is 490 pounds of mail.
1050 - 490 = 560
Now we need to find out the maximum number of passengers that can board the plane.
70p = 1050
We know that there are 560 avalible pounds left on the plane
70 x 8 = 560
560 + 490 = 1050.
Well if we go back to the question it says less than 1050. This means that 8 passengers times 70 pounds each would not be correct because the small airplane can carry less than 1050 pounds.
70 x 7 = 490
490 + 490 = 980
980 is less than 1050
So the answer would be 7 passengers.
7 Passengers is the maximum amount of passengers that can be taken.
I hope this helps!
Combination method: add the two equations together
5) <span>4x-9y=1 6) 3x - 2y = 14
+( - 4x+6y=-2 ) + (2x + 2y = 6)
---------------------- -------------------
0 - 5y = -1 5x + 0 = 20
-5y = -1 5x = 20
isolate the y isolate the x
-5y / -5 = -1/-5 5x/5 = 20/5
y = 1/5 x = 4
</span>4x-9y=1 3x - 2y = 14
4x - 9(1/5) = 1 3(4) - 2y = 14
4x - 9/5 = 1 12 - 2y = 14
4x - 9/5 (+9/5) = 1 (+9/5) 12 (-12) - 2y = 14 (-12)
4x = 14/5 -2y = 2
4x/4 = 14/5(/4) -2y(/-2) = 2(/-2)
x = 14/20 y = -1
Elimination method
7) 4x + 3y = 29 + (5x + 2y = 24)
eliminate one of the variables by multiply the number to both sides
2 (4x + 3y = 29) + 3 (5x + 2y = 24)
8x + 6y = 58
-( 15x + 6y = 72)
----------------------
-7x = - 14
-7x/-7 = -14/-7
x = 2
4(x) + 3y = 29
4(2) + 3y = 29
3y + 8 = 29
3y + 8 (-8) = 29 (-8)
3y = 21
3y/3 = 21/3
y = 7
8) like #7, you must eliminate one of the variables by multiply the number to both sides
-4x - 2y = 14
-10x + 7y = -25
7(-4x - 2y = 14)
-2(-10x + 7y = -25)
-28x - 14y = 98
- (20x -14y = -25)
-----------------------
-48x = 123
-48x/-48 = 123/-48
x = -2.56
-4(-2.56) - 2y = 14
10.24 - 2y = 14
10.24(-10.24) - 2y = 14 (-10.24)
-2y = 3.76
-2y/-2 = 3.76/-2
y = -1.88
hope this helps
The answer is <u><em>0.76075</em></u>!
<em>Hope this helps!</em>