Question

50 money prize for solve

Answer 1

-7.5

Alternatively,

-0.5(units^-1) + (-4(units^0)) + (-3(units))

Explanation:

On graph, only clearly defined points:

1. x = -3 , y = 0

2. x = -3 , y = -8

3. x = 5 , y = -4

So for:

1. -3 = c ( + a×(0^2) + b×0)

And

2. -3 = a×((-8)^2) + b×(-8) + c = 64×a + (-8)×b + c

Since c = -3 ==> 64×a - 8×b = 0

Simplified ==> 8×a - b = 0 ==> b = 8×a

3. 5 = a×((-4)^2) + b×(-4) + c = 16×a + (-4)×b + c

Since c = -3 ==> 16×a - 4×b = 5 - (-3) = 8

Simplified ==> 4×a - b = 2

Since b = 8×a ==> 4×a - (8×a) = 2

Simplified ==> 2×a - 4×a = 1

==> -2×a = 1

==> a = -0.5

Since b = 8×a ==> b = 8×(-0.5) = -4

So...

c = -3

b = -4

a = -0.5

Then...

a + b + c = -0.5 - 4 - 3 = -7.5