Answer:
see explanation
Step-by-step explanation:
To find the roots factor the left side
x³ + 7x² + 12x = 0 ← factor out x from each term
x(x² + 7x + 12) = 0
x(x + 3)(x + 4) = 0
Equate each factor to zero and solve for x
x = 0
x + 3 = 0 ⇒ x = - 3
x + 4 = 0 ⇒ x = - 4
Roots are x = - 4, x = - 3, x = 0
Answer:
The most likely solution sought is 13:
Beginning with 3: subtract 9, add 18, subtract 8, add 16, subtract 7, add 14, etc. Each time, reduce the number subtracted by one, and double that number to add.
So, beginning with 3: 3-9 = -6, -6+2(9) = 12, 12-8 = 4, 4+2(8) = 20, 20-7 = 13, etc.
*****
Step-by-step explanation:
Answer:
x = 1/2 y = -5/2
Step-by-step explanation:
Since we already know an equation for y, we just need to plug it into the other equation.
21x - 7(-5x) = 28
21x + 35x = 28
56x = 28
x = 1/2
Now that we know x, we substitute it into the other equation, to find y.
y = -5x
y = -5(1/2)
= -5/2
Answer:
-5t² + 2t - 3
Step-by-step explanation:
G = 3t2 – 5t + 6
P = -8t² + 7t – 9
G + P
= (3t² – 5t + 6) + (-8t² + 7t – 9)
= 3t² - 8t² - 5t + 7t + 6 - 9
= -5t² + 2t - 3