Answer:
2x+y=7
5x-3y=1
we do reduction.
3(2x+y=7)............6x+3y=21
5x-3y=1............... 5x-3y=1
11x=22.......x=22/11.............. x=2
if x=2
2x+y=7
2(2)+y=7
4 +y=7
y=7-4
y=3
solution:
x=2 y=3
The value of x is 8 when y = 12 if variables x and y have proportional relationship.
According to the given question.
Variables y and x have proportional relationship.
⇒ y ∝ x
Let k be the constant of proportionality.
⇒ y = kx
Also, it is given that
y = 21 when x = 14
Substitute the value of y = 21 and x = 14 in y = kx to find the value of k.
21 = k(14)
⇒ k = 21/14
⇒ k = 3/2
Therefore, the value of x when y = 12
y = kx
⇒ 12 = (3/2)x
⇒ 12 × 2 = 3x
⇒ 24 = 3x
⇒ x = 24/3
⇒ x = 8
Hence, the value of x is 8 when y = 12.
Find out more information about proportional relationship here:
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Answer:
C) 201
Step-by-step explanation:
Margin of error = critical value × standard error
ME = CV × SE
Assuming n > 30, we can approximate CV with a normal distribution. At P = 99%, CV = 2.576.
SE = σ / √n
SE = 1100 / √n
Therefore:
200 = 2.576 × 1100 / √n
n = 201
Multiply 8×3=24 (whole number by denominator)
then, add 2=26 (answer plus numerator)
keep same denominator
answer: 26/3