The answer is A cause 30% is 0.7 and f(n-1) equals the amount being sold the +50 is for every 50 new one and the the 235 is for what they started with
Answer:
y = 1/6 x^2 + 8/3 x + 49/6
Step-by-step explanation:
This is a parabola which opens upwards.
The distance of a point (x, y) from the focus is
√[(x - -8)^2 + (y - -1)^2] and
the distance of the point from the line y = -4
= y - -4
These distances are equal for a parabola so:
√[(x - -8)^2 + (y - -1)^2] = y + 4
Squaring both sides:
(x + 8)^2 + (y + 1)^2 = (y + 4)^2
x^2 + 16x + 64 + y^2 + 2y + 1 = y^2 + 8y + 16
x^2 + 16x + 64 + 1 - 16 = 8y - 2y
6y = x^2 + 16x + 49
y = 1/6 x^2 + 8/3 x + 49/6 is the equation of the parabola.
Answer:
x > 7/4
Step-by-step explanation:
3(x + 7) < 7(x + 2)
Expand brackets: 3x + 21 < 7x + 14
Subtract 14 from both sides: 3x +7 < 7x
Subtract 3x from both sides: 7 < 4x
Divide both sides by 4: 7/4 < x
Therefore x > 7/4
