P = 390,00 + 4000x
450,000 people - (15years x 4000) = 390k in 2010
15 years is the difference between 2010 and 2025
subtract 60k (that is the 15 years multiplied by 4k) from 450k and you get 390k.
Sorry if my explanations suck, I'm not great at explaining my thought process
Answer: 
Step-by-step explanation:
Since, The total number of student = 300
Out of which,
The number of students who are only in Maths = 120
And, The number of students who are only in Science = 50
While, the students who are not from any subject = 100
Hence, the number of student who are from both maths and science = Total student - Maths student (only) - science student (only) - None
= 300 - 120 - 50 - 100
= 30
That is, there are 30 students who are both from science and maths,
Thus, the probability of selecting one student who is both from maths and science = 30/300 = 1/10
Answer:
18. b
19. b
Step-by-step explanation:
The linear combination method involves multiplying, adding and subtracting in such a way that allows one variable to be eliminated in the addition or subtraction step. This leaves the other variable alone, allowing its value to be determined.
1. <span>5m+3n=41, 3m−6n=9
Multiply 1st equation by 2: 10m + 6n = 82
Add to 2nd equation: 13m = 91
Divide by 13: m = 7
Substitute back to 1st equation: n = 2
Therefore m = 7 and n = 2.
2. </span><span>6g+8h=40 −6g+2h=−20
Add both equations: 10h = 20
Divide by 10: h = 2
Substitute to 1st equation: g = 4
Therefore g = 4 and h = 2.
3. </span><span>9x+5y=35 2x+5y=0
Subtract 1st equation by the 2nd equation: 7x = 35
Divide by 7: x = 5
Substitute back to the 1st equation: y = -2
Therefore x = 5 and y = -2.
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Answer:
D
Step-by-step explanation:
D has a repeating x value. Functions are only supposed to have one input for everyone output. ( no repeating x values)