20. (2) 14
A perfect square trinomial will factor into two expressions that are the same, for example: x^2 + 6x + 9 = (x + 3)(x + 3). Since this problem has a C value of 49, it will factor into (x + 7)(x + 7). 7 doubled is 14, therefore one possible value of B is 7.
21. (4) 2, -12
x^2 + 10x + 25 = 24 + 25
(x + 5)^2 = 49
x + 5 = +/- 7
x = 2, -12
22. (3) 3 + sqrt(17)
x^2 - 6x = 8
Complete the Square
x^2 - 6x + 9 = 8 + 9
(x - 3)^2 = 17
x - 3 = +/- sqrt(17)
x = 3 + sqrt(17), 3 - sqrt(17)
23. (1) 1, -5
x^2 + 4x - 5 = 0
x^2 + 4x = 5
x^2 + 4x + 4 = 5 + 4
(x + 2)^2 = 9
x + 2 = +/- 3
x = 1, -5
Hope this helps!
Answer:
C. 49
Step-by-step explanation:
When you put the equation together it becomes: 7(9)-14=49
Answer: option B is correct
Step-by-step explanation:
The formula for determining the area of cross section of a trapezoid is expressed as
Area = 1/2(a + b)h
Where
a and b are the length of The bases are the 2 sides of the trapezoid which are parallel with one another.
h represents the height of the trapezoid.
From the information given,
a = h1 = 11 inches
b = h2 = 15 inches
If It has an area of 52 inches² , then
52 = 1/2(11 + 15)h
Cross multiplying by 2, it becomes
52 × 2 = (11 + 15)h
104 = 26h
h = 104/26 = 4 inches