Answer:
The number of baseball card to begin with is 143
Step-by-step explanation:
Let The number of baseball cards = x
The number of sold baseball card = 60% of x
= 0.6 x
The number of left baseball card = x - 0.6 x = 0.4 x
The number of card gave away = 30 % of left cards
= 0.3 × 0.4 x = 0.12 x
The number of card left in his possession = 40
So, 0.6 x + 0.12 x + 40 = x
Or, 40 = x - 0.6 x - 0.12 x
Or, 40 = 0.28 x
∴ x = 
= 142.85 ≈ 143
Hence The number of baseball card to begin with is 143 Answer
Answer:
9 cm
Step-by-step explanation:
If the scale is 3cm:18 km, then x cm : 54km will be the distance between Riverside and Smithville. Since 18 *3 = 54 then 3cm * 3 = 9cm. On the map they are 9 cm apart.
Answer:A
Step-by-step explanation:
Answer:
Step-by-step explanation:
This is a positive parabola so it opens upwards. The equation for the directrix of this parabola is y = k - p. k is the second number in the vertex of the parabola which is (0, 0), but we need to solve for p.
The form that the parabola is currently in is
so that means that 
. We can use that to solve for p in the formula
so
which simplifies to
which gives us that
p = 2. Now to find the directrix:
y = k - p becomes
y = 0 - 2 so
y = -2, choice A.
