Answer:
(x - 43)(x + 3)
Step-by-step explanation:
consider the factors of the constant term (- 129) which sum to give the coefficient of the x- term (- 40)
the factors are - 43 and + 3 , since
- 43 × + 3 = - 129 and - 43 + 3 = - 40 , then
x² - 40x - 129 = (x - 43)(x + 3) ← in factored form
Selection C is appropriate.
_____
A. The population is constant at 8.
B. The population is constant at 24.
C. Matches the problem description.
D. The initial population is 24 and after 1 hour is 72.
6. 3X6= 4xm
18=4m
Divide by 4
M=4.5
7.14 x5= b^2
70=b^2
Sq rt of 70
8.4
Answer:
x = 2
y = 1
Step-by-step explanation:
3x - y = 5..............(1)× 1
2x + y = 5...….......(2)× 1
3x - y = 5..............(3)
2x + y = 5.............(4)
Cancel y
3x + 2x = 5 + 5
5x = 10
Divide both sides by 5
x = 2
Substitute for the value of y
3x - y = 5
3(2) - y = 5
6 - y = 5
6 - 5 = y
1 = y
y = 1
In the balanced reaction
2 Fe + O₂ → 2 FeO
2 moles of iron (Fe) react with 1 mole of molecular oxygen (O₂) to produce 2 moles of iron oxide (FeO). The ratio of Fe to FeO is 1-to-1, so if one starts with 42.4 mol of Fe, one will end up with the same amount of FeO, 42.4 mol.
Look up the molar mass of Fe and O:
• Fe = 55.845 g/mol
• O = 15.999 g/mol
Then the molar mass of FeO is approximately 71.835 g/mol, and so the mass of 42.4 mol of FeO is
(42.4 mol) × (71.835 g/mol) ≈ 3050 g
