Answer:
33+12t−21t^2
Step-by-step explanation:
(2t-7)²-(5t-4)²
Use binomial theorem (a−b)^2 = a^2−2ab+b^2 to expand (2t-7)².
4t^2−28t+49−(5t-4)²
Use binomial theorem (a−b)^2 = a^2−2ab+b^2 to expand (5t-4)².
4t^2−28t+49−(25t^2−40t+16)
To find the opposite of 25t^2
−40t+16, find the opposite of each term.
4t^2−28t+49−25t^2−40t+16
Combine 4t^2 and −25t^2 to get −21t^2.
−21t^2−28t+49+40t−16
Combine −28t and 40t to get 12t.
−21t^2+12t+49−16
Subtract 16 from 49 to get 33.
−21t^2+12t+33
Swap terms to the left side.
33+12t−21t^2
I hope this helped!
Answer: 16 men
32 women
38 children
Step-by-step explanation:
Let x represent the number of men in the group.
Let y represent the number if women in the group.
Let z represent the number of children in the group.
A group of 86 people consist of men women and children. This means that
x + y + z = 86 - - - - - - - - - - - - 1
There are twice as many women than there are men. It means that
x = y/2
There are 6 more children than there are women. This means that
z = y + 6
Substituting x = y/2 and z = y + 6 into equation 1, it becomes
y/2 + y + y + 6 = 86
multiplying through by 2, it becomes
y + 2y + 2y + 12 = 172
5y = 172 - 12 = 160
y = 160/5 = 32
x = y/2 = 32/2
x = 16
z = y + 6 = 32 + 6
z = 38
Answer:
y = -2
Step-by-step explanation:
Answer:
The probability that a book picked at random is either a work written by an author who writes only nonfiction or a work written by a man is 75.8%.
Step-by-step explanation:
The probability, in this case, has to be calculated using the sum rule because the events are independent.
P = P(men) + P(non-fiction) - P(men non-fiction); where P is the probability. It means the probability that the random book was written by a man plus the probability that the random book was non-fiction minus the probability that the random book was written by a man who writes non-fiction. The probability that the random book was written by a man who writes non-fiction has to be subtracted, if not you will be duplicating it.
Facts:
P(men) = 60% = 99/165
P(non-fiction) = 40% = 66/165
P(men non-fiction) = 40/165
P = P(men) + P(non-fiction) – P(men non-fiction)
P = 99/165 + 66/165 – 40/165
P = 125/165
P = 0.758 or 75.8%
9514 1404 393
Answer:
yes
Step-by-step explanation:
We can substitute the proposed solution values and see if the inequality is true.
0.50x +0.80y ≥ 20
0.50(20) + 0.80(32) ≥ 20
10 + 25.6 ≥ 20
35.6 ≥ 20 . . . . . . true; (20, 32) is a solution
