13, because 78 postcards divided by 6 cards per board = 13 poster boards
F(x) = x² + x - 20 = x² + 5x - 4x - 20 = x(x + 5) - 4(x + 5) = (x + 5)(x - 4)
f(x) = 0 ⇔ (x + 5)(x - 4) = 0 ⇔ x + 5 = 0 or x - 4 = 0 ⇒ x = -5 or x = 4
Answer: C. x = -5 and x = 4.
Answer:
The quantity of clover seeds in pounds to be added is 11.14
Step-by-step explanation:
Let
x -----> the quantity of poppy seeds in pounds
y -----> the quantity of clover seeds in pounds
we know that
-----> equation A
----> equation B
substitute equation B in equation A and solve for y
therefore
The quantity of clover seeds in pounds to be added is 11.14
If there is 20 pencils there will be 5 erasers 20:5