Answer:
m=-1
Step-by-step explanation:
2x+3y=11............. (eqn 1)
2x-4y=-24...........(eqn 2)
Subtract eqn 1 from eqn 2
7y=35
y=5
Substitute for y in eqn 1
2x+3(5)=11
2x+15=11
2x=11-15
2x=-4
x=-2
y=mx+3
5=-2m+3
5-3=-2m
2=-2m
m=-1
Answer:
-2x^2 + 3x -1
Step-by-step explanation:
y = ax^2 + bx + c
(0,-1):
-1 = a(0)^2 + b(0) + c
-1 = 0 + 0 + c
-1 = c
(1,0):
0 = a(1)^2 + b(1) + c
0 = a + b + c
(2,-3):
-3 = a(2)^2 + b(2) + c
-3 = 4a + 2b + c
Replace c with -1
0 = a + b -1
1 = a + b
-3 = 4a + 2b -1
-2 = 4a + 2b
-1 = 2a + b
Solve:
2a + b = -1
-1a - b = -1
a = -2
2a + b = -1
-2a -2b = -2
-b = -3 divide both by -1: b = 3
a = -2; b = 3; c = -1
y = ax^2 + bx + c or y = -2x^2 +3x -1
Answer:
486
Step-by-step explanation:
We can find the answer by solving the two equations simultaneously.
equation 1: y = -0.4x^2 +3xequation 2: x + y = 10
We need to write equation to with y as the subject:equation 2: y = 10 - x
equation 1 = equation 2:
10 - x = -0.4x^2 + 3x0.4x^2 - 4x + 10 = 02x^2 - 20 + 50 = 0(2x - 10)(x - 5) = 0x = -10/2 or x = 5
But x >= 0 (the question says it's a height above the water), so x = 5
Substituting x = 5 into one of the equations:
y = 10 - x
y = 10 - 5
y = 5
So the answer is C
The box and whisker plot for the information will be as follows:
<span>79,70,73,84,83,88,75,72,76,68,68,79,84,74,75,85,67,78,69,80
From the table the average is 76.5</span>