Because of the added insulation to control the temperature inside,the cost of heating and cooling went down
So
a be first term and d be common difference
- a+a+2d+a+4d+a+6d+a+9d=17
- 5a+21d=17--(1)
And
- a+d+a+3d+a+5d+a+7d+a+9d=15
- 5a+25d=15--(2)
Eq(1)-Eq(2)
Put in second one
- 5a+25d=15
- a+5d=3
- a+5/2=15
- a=15-5/2
- a=25/2
Answer:
see explanation
Step-by-step explanation:
(a)
Given
x² + 5x + 6
Consider the factors of the constant term ( + 6) which sum to give the coefficient of the x- term ( + 5)
The factors are 3 and 2, since
3 × 2 = 6 and 3 + 2 = 5, hence
x² + 5x + 6 = (x + 3)(x + 2) ← in factored form
(b)
To solve
x² + 5x + 6 = 0 ← use the factored form, that is
(x + 3)(x + 2) = 0
Equate each factor to zero and solve for x
x + 3 = 0 ⇒ x = - 3
x + 2 = 0 ⇒ x = - 2
This question is soooo easy
Step-by-step explanation:
(3x)^2+(5)^2+2.3x.5
9x^2+25+30x
