Answer:
C(x) = 
Step-by-step explanation:
Data provided in the question:
Area of the field = 3600 square feet
Fencing charges = $3.50 per foot
Let the side along the river be 'x' feet and the other side of the 'B'
now,
Area of rectangle = Bx = 3600 square feet
or
B =
feet
and total length to be fenced = x + 2B
therefore,
Total cost of fencing = Fencing charges × total length to be fenced
or
Total cost of fencing = $3.50 × ( x + 2B )
substituting the value of B from (1)
Total cost of fencing, C(x) = 
or
C(x) = 
Answer:
see explanation
Step-by-step explanation:
Given
x² - 3x - 40 = 0
Consider the factors of the constant term (- 40) which sum to give the coefficient of the x- term (- 3)
The factors are - 8 and + 5, since
- 8 × 5 = - 40 and - 8 + 5 = - 3, thus
(x - 8)(x + 5) = 0 ← in factored form
Equate each factor to zero and solve for x
x - 8 = 0 ⇒ x = 8
x + 5 = 0 ⇒ x = 5
------------------------------------------------------
Given
4x² - 81 = 0 ← this is a difference of squares and factors in general as
a² - b² = (a + b)(a - b), thus
4x² - 81
=(2x)² - 9²
= (2x + 9)(2x - 9) = 0 ← in factored form
Equate each factor to zero and solve for x
2x + 9 = 0 ⇒ 2x = - 9 ⇒ x = - 
2x - 9 = 0 ⇒ 2x = 9 ⇒ x = 
Answer:
c)
Step-by-step explanation:
Use 49 instead of 14 for 7²
Reason: 7² = 7 * 7 = 49
Not 14 as 7*2 = 14
Answer:
Yes
Step-by-step explanation:
2 times 19=38
1 times 19=19