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
The surface area of triangular prism is 117.12 mm²
<u>Explanation:</u>
Base side, a = 9 mm
Base side, b = 6.6 mm
Base side, c = 5.2 mm
Height, h = 4 mm
Total surface area = ?
We know,
Surface area, A = 2 Ab ( a+b+c) h
Ab = √s(s-a) (s-b) (s-c)
s = a+b+c/2
Solving for A
A = ah + b h + ch + 1/2 √ -a⁴ + 2(ab)² + 2(ac)² - b⁴ + 2 (b c)² - c⁴
A = 9.4 + 6.6 X 4 + 5.2 X 4 + 1//2 √ -9⁴ + 2(9 X 6.6)² + 2(9 X 5.2)² - (6.6)⁴ + 2 (6.6 X 5.2)² - (5.2)⁴
A = 117.12 mm²
Therefore, the surface area of triangular prism is 117.12 mm²
Hmm, this answer is mathematically incorrect. If the question has no errors, 38 can go into 7 0 times, it can't because its bigger than 7.
However, if it were meant to be the other way round, how many times does 7 go into 38, the answer would be 5.
You just have to look at the form of the equations
The only linear equations would be y = mx + b and Ax + By = C
