Answer:
what is the question?????????????????????
In the second equation it is actually going on to be +2x^2 -4x-2 then your going to combine like terms. So it will be 5x^2-10. Because he 4x’s are going to eliminate each other.
Answer: the probability that the number x of correct answers is fewer than 4 is 0.61
Step-by-step explanation:
Let x be a random variable representing the answers to the SAT questions. This is a binomial distribution since the outcomes are two ways. It is either the answer is correct or incorrect. Also, the probability of success or failure is constant for each trial. The probability of success, p = 0.35
The probability of failure, q would be 1 - p = 1 - 0.35 = 0.65
We want to determine P(x < 4)
n = number of trial = 9
x = 4
From the binomial distribution calculator,
P(x < 4) = 0.61
25x + 15y = 265
x+y = 13
Step-by-step explanation:
Step 1:
Given
Number of shirts Leah can iron in an hour = 25 shirts
Number of shirts Christopher can iron in an hour = 15 shirts
Total number of hours worked by both = 13 hours
Total number of shirts ironed by them = 265 shirts
Step 2 :
Let x represent the number of hours Leah works and y represent the number of hours Christopher works
Leah irons 25 shirts in one hour, so in x hours he would iron 25x shirts
Christopher irons 15 shirts in one hour, so in y hours he would iron 15y shirts
Given total shirts ironed by them together is 265 , we have
25x + 15y = 265
They worked a combined of 13 hours, so
x+y = 13
Step 3:
The system of equations that could be used to determine the number of hours Leah worked and the number of hours Christopher worked are ,
25x + 15y = 265
x+y = 13
5x + 4y = 8
2x - 3y = 17
(multiply the bottom equation by -2.5)
5x + 4y = 8
+
-5x + 7.5y = -42.5
—————————
(5x’s cancel out)
11.5y = -34.5
—— ———
11.5 11.5
y = -3
(Plug y in the equations to find x)
5x + 4(-3) = 8
5x - 12 = 8
5x = 20
—-
5
x = 4
(confirm using the other equation)
2(4) - 3(-3) = 17
8 + 9 = 17
17 does equal 17!
