B. (k+10f)(k-5f) you can tell in 2 ways. 1. if the second sign is neg then the signs in the factors are going to be one neg and one positive so that knocks out C and D. Then you look at the second term and since the 5 is positive then the 10 has to be positive so you end up with a positive 5kf.
The second way is to FOIL them out. When you check B you get

combine your like terms and you have your original expression of

Hope that helps
First integrate the entire thing by letting multiplying by 1/2 the entire expression raised to exponent 1/2 - 1. That is,
0.5(1 + x³)^-0.5
Then, multiplying this by the derivative of those inside the parentheses. The final answer would be,
(0.5)((1 + x³)^-0.5)(3x²)
number 7 is as follows Answer: C18.9
Step-by-step explanation:
The perimeter is the length of the outline of a shape. To find the perimeter of a rectangle or square you have to add the lengths of all the four sides. so (5.65x2)+(3.8x2)=18.9 cm
Answer:
x = 26, y = 9
Step-by-step explanation:
Add the bottom equations and set them equal to 180
8x -28 = 180
8x = 208 divide each by 8
x = 26
Find the bottom right, 3(26) - 11
78 - 11 = 67
The unlabeled top left box is also equal to 67 degrees.
So 2y + 5 = 23
2y = 18
y = 9
I honestly don’t know
Sorry sweety