All these equations are in the form of ax^2 + bx + c = 0, where a, b, and c are some numbers. the discriminants of equations like this are equal to b^2 - 4ac. if the discriminant is negative, there are two imaginary solutions. if the discriminant is positive, there are two real solutions. if the discriminant is 0, there is one real solution.
<span>x^2 + 4x + 5 = 0
</span>b^2 - 4ac
4^2 - 4(1)(5)
16-20
-4, two imaginary solutions.
<span>x^2 - 4x - 5 = 0
</span>b^2 - 4ac
(-4)^2 - 4(1)(-5)
16 + 20
36, two real solutions.
<span>4x^2 + 20x + 25 = 0
</span>b^2 - 4ac
20^2 - 4(4)(25)
400 - 400
0, one real solution.
Answer:
480 cm^3
Step-by-step explanation:
Total volume is the sum of the volumes of the 3 cuboids.
Cuboid at the bottom:
V = l×b×h
V = 12 × 5 × 4 = 240
Both on top are identical.
Their height is 10-4= 6 cm
Each has volume = 5×4×6 = 120
Total Volume = 240 + 120 + 120
= 480 cm^3
43x5= 215
215 pupils
215-200=15
15 seats
X = y - 5
x = 1 - y / 3
I hope this helps. :)
