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:
minos anos
Step-by-step explanation:
Answer:check the pic
Step-by-step explanation:
The distance formula is d=\sqrt{(x_{2}, x_{1})^{2} +(y_{2}, y_{1})^2
7=x1
4=y2
-8=x2
4=y2
Just plug in the missing values into the equation and solve the equation :)
Answer:
x = -4 (multiplicity 2)
Step-by-step explanation:
x^2 + 8x + 16 = 0
You need 2 numbers whose product is + 16 and whose sum is +8.
They are +4 and + 4 so the factors are:-
(x + 4)(x + 4)
(x + 4)(x + 4) = 0
x = -4 (multiplicity 2)
(There are 2 zeroes each of value -4)
