Answer:
The number of dogs that had both Lyme disease and arthritis is 18
Step-by-step explanation:
Let x represent dogs that have both Lyme disease and arthritis
Dog with only Lyme disease = 42 - x
Dog with only arthritis = 96 - x
The sum of the 3 category should give 120
x + (42 - x) + (96 - x) = 120
Collect like terms and solve
x - x - x + 42 + 96 = 120
-x + 138 = 120
138 - 120 = x
x = 18
Dog with only Lyme disease = 42 - x = 42 - 18 = 24
Dog with only arthritis = 96 - x = 96 - 18 = 78
Therefore, the number of dogs with both Lyme disease and anthritis is 18.
5x + 3y= 8.50
3x + 2y= 5.25
Lydia is the first equation. She bought 5 pounds of apples which is x and bought 3 pounds of bananas which is y. Basically, remember each banana and apple weighs a price per pound. We don't know the price so we just put an x. This is the same for the second equation
The equation to find the air pressure (P(h)) at a height above sea level (h) is given by
Where,
- P(h) is the new pressure at height h
is the air pressure at sea level, and- h is the height (measured in meters).
We want to know the new pressure that is 65% of 
. So we should substitute 
in P(h) (new pressure) to get the equation:
. Answer choice B is the correct one.
ANSWER: B
