snakes

[Tiger-T]

A biologist recorded 9 snakes on 21 acres in one area and 13 snakes on 47 acres in another area. Let y be the number of snakes in x acres. Write a linear equation for the number of snakes.

A) y = x + 12
B) 13y = 2x + 75
C) 13y = 2x + 12
D) 13y = 2x - 75

X1 = 21; Y1 = 9, and X2 = 47; Y2 = 13
( 21,9) & (47,13)
13 – 9/47 – 21 = 4/26 = 2/13 = the slope


y - y1 = m(x - x1)
y – 9 = 2/13 (x – 21)
y – 9 = 2/13x - 42/13
y – 9 + 9 = 2/13x - 42/13 + 9
y = 2/13x – 42/13 + 117/13
y = 2/13x + 75/13


My guess is that the answer is either B or D; I prefer B. Am I correct?

 

[Mrspi]

A biologist recorded 9 snakes on 21 acres in one area and 13 snakes on 47 acres in another area. Let y be the number of snakes in x acres. Write a linear equation for the number of snakes.

A) y = x + 12
B) 13y = 2x + 75
C) 13y = 2x + 12
D) 13y = 2x - 75

X1 = 21; Y1 = 9, and X2 = 47; Y2 = 13
( 21,9) & (47,13)
13 – 9/47 – 21 = 4/26 = 2/13 = the slope


y - y1 = m(x - x1)
y – 9 = 2/13 (x – 21)
y – 9 = 2/13x - 42/13
y – 9 + 9 = 2/13x - 42/13 + 9
y = 2/13x – 42/13 + 117/13
y = 2/13x + 75/13


My guess is that the answer is either B or D; I prefer B. Am I correct?

In most mathematics, our "preference" is not what determines whether an answer choice is or is not correct.

So, you can "prefer" B all you want, but in my opinion it would be wise to check to see if B is, in fact, the correct choice. Since the points (21, 9) and (47, 13) are BOTH supposed to lie on the line which the equation represents, then the correct equation will be true when you use 21 for x and 9 for y, AND when you use 47 for x and 13 for y.

Did you check to see which of your "possible" answer choices works?

 

[Denis]

y = 2/13x + 75/13
My guess is that the answer is either B or D; I prefer B. Am I correct?

Multiply by 13: 13y = 2x + 75

IMPORTANT: NEVER use word "guess" when giving answer; teacher will simply give you ZERO!

 

[Tiger-T]

Yes B fits; thank you!

A biologist recorded 9 snakes on 21 acres in one area and 13 snakes on 47 acres in another area. Let y be the number of snakes in x acres. Write a linear equation for the number of snakes.

A) y = x + 12
B) 13y = 2x + 75
C) 13y = 2x + 12
D) 13y = 2x - 75

X1 = 21; Y1 = 9, and X2 = 47; Y2 = 13
( 21,9) & (47,13)
13 – 9/47 – 21 = 4/26 = 2/13 = the slope


y - y1 = m(x - x1)
y – 9 = 2/13 (x – 21)
y – 9 = 2/13x - 42/13
y – 9 + 9 = 2/13x - 42/13 + 9
y = 2/13x – 42/13 + 117/13
y = 2/13x + 75/13


My guess is that the answer is either B or D; I prefer B. Am I correct?

In most mathematics, our "preference" is not what determines whether an answer choice is or is not correct.

So, you can "prefer" B all you want, but in my opinion it would be wise to check to see if B is, in fact, the correct choice. Since the points (21, 9) and (47, 13) are BOTH supposed to lie on the line which the equation represents, then the correct equation will be true when you use 21 for x and 9 for y, AND when you use 47 for x and 13 for y.

Did you check to see which of your "possible" answer choices works?

 

[Denis]

Q: did you hear about the poor snake?
A: it didn't have a pit to hiss in !