Answer:
c. f(x)=x(x+2)(x-1)(x-4)
Step-by-step explanation:
Where it says "as x goes to negative infinity" then "y goes to infinity" (that's the part with the infinity symbols) that means the graph is going up at it's left end. This curve is a quartic (4th degree) which means its left and right ends are kind of parabola-ish, but the middle is not the neat u-ish, v-ish shape of a parabola; it's more like a wonky, noodle-ish wavy affair. Anyway, LIKE a parabola when the beginning of the equation is positive, the two ends point up. That's what's happening here and so we can eliminate b. and d. as potential answers.
Since -2, 0, 1, 4 are zeros (which are solutions...and also x-intercepts) we can find the factors of the function.
If x = -2
ADD 2 to both sides.
x + 2 = 0
This means (x+2) is a factor.
This is enough info to select answer c. but let's verify the other factors.
If x = 1
SUBTRACT 1 from both sides.
x - 1 = 0
Thus means (x - 1) is a factor.
If x = 4
SUBTRACT 4 from both sides.
x - 4 = 0
(x - 4) is a factor.
You can see c. has all these factors as well as x, because x=0 already, so x is a factor too.
I think of this as a working backwards problem, bc usually you have to factor and solve. This one, you have solutions (which are zeros and x-intercepts) and work backwards to find factors and multiply them together to find the function.
Answer:
amt. the shop spends on 40 pairs
= $11 × 40
= $440
amt. paid extra (due to fixed cost) per pair
= ($450 - $440) ÷ 40
= $0.25
amt. per pair to break even
= $11 + $0.25
= $11.25
Answer: sally initially has $240, Tom initially has $180.
Step-by-step explanation:
Let initial amount of money sally has = x
Then, initial amount tom has = 75% * x = 0.75x
Now to present,
Amount sally has = x -120
Amount tom has = [x - 120] + [50% * (x-120)]
= x - 120 + 0.5x - 180
= 1.5x - 180
Since Tom didn't spend, it means this is the same amount tom has then we equate both equations.
0.75x = 1.5x - 180
180 = 0.75x
x = 240
Therefore, initial money of sally of sally = $240
Initial money of tom = 240 * 0.75 = $180.
