Answer:
11. 78
12. 4x² - 3x - 1
Step-by-step explanation:
11. Sum of n whole numbers = ½(n² + n)
Multiply
½*n² + ½*n
= n²/2 + n/2
To find the sum of the first 12 whole number, substitute 12 for n into the equation.
= 12²/2 + 12/2
= 144/2 + 12/2
= 72 + 6
= 78
12. Area of trapezoid = ½(a + b)*h
Where,
a = 5x - 4
b = 3x + 2
h = x + 1
Area = ½(5x - 4 + 3x + 2)*(x + 1)
Area = ½(8x - 2)*(x + 1)
Area = ½[8x(x + 1) -2(x + 1)]
= ½[8x² + 8x - 2x - 2]
Add like terms
= ½(8x² - 6x - 2)
= ½(8x²) - ½(6x) - ½(2)
= 4x² - 3x - 1
Answer:
Precambrian period
Step-by-step explanation:
Since the Great oxidation period = 2.4 Billion years ago era = Precambrian period.
Micro-fossils attributed to cyanobacteria are abundant during the Proterozoic that came later 2,5 billion years ago and ended 540 million years ago,
Answer:The amount to be paid within the discount period is $980
Step-by-step explanation:
The term 2/10, n45
means that 2% discount is offered if the amount of invoice is paid within 10 days from the date of invoice .
n/45 means that the buyer will pay the full amount within 45 days if he /she does not pay within the discount period of 10 days .
Now if the amount is to be paid within the discount period, the amount will be
Amount to be paid= $1000- 2% of 1000
= $1000-20
=$980
Divide by -8 (change inequality sign direction)
Response:
Answer:
(0, -3)
Step-by-step explanation:
y = 3x - 3
y = x - 3
In the solution to the system of equations, y is the same number for both of those functions. So 3x - 3 = x - 3.
Then solve for x:
3x - 3 = x - 3
Add 3 to both sides
3x = x
Subtract x from both sides
2x = 0
Divide both sides by 2
x = 0
Now that you have x, substitute it in one of the equations:
y = 3x - 3
y = 3(0) - 3
y = -3
x is 0 and y is -3, so the solution to the equation is (0, -3)
