Answer:
U ={ Parallelograms}
A= { Parallelogram with four congruent sides}={ Rhombus,Square}
B ={ Parallelograms with four congruent angles} ={ Rectangle, Square}
So, AB= { Square}
So among all the parallelograms "Square" is the only parallelogram which has all congruent sides as well as all congruent angles.
The equation for exponential decay is
, where <em>a</em> is the initial amount, <em>b</em> = 1 + <em>r</em> (the growth rate as a decimal number) and <em>x</em> is the number of time periods (in this case, minutes). Substituting the information we have:
. To the nearest tenth of a gram, this would be 1.0 grams.
There were 14 hens and 18 pigs in the backyard
Step-by-step explanation:
Katie was visiting her grandpas farm
- She saw only hens and pigs
- Katie counted 32 heads and 100 feet in the backyard
We need to find how many hens and pigs in the backyard
Assume that there are x hens and y pigs in the backyard
∵ There are x hens and y pigs in the backyard
∵ There are 32 heads
∴ x + y = 32 ⇒ (1)
∵ Each hen has 2 feet
∵ Each pig has 4 feet
∵ There are 100 feet
∴ 2x + 4y = 100 ⇒ (2)
Let us solve the system of equations to find how many hens and pigs
Multiply equation (1) by -2 to eliminate x
∴ -2x - 2y = -64 ⇒ (3)
- Add equations (2) and (3)
∴ 2y = 36
- Divide both side by 2
∴ y = 18
Substitute the value of y in equation (1) to find the value of x
∵ x + 18 = 32
- Subtract 18 from both sides
∴ x = 14
There were 14 hens and 18 pigs in the backyard
Learn more:
You can learn more about the system of equations in brainly.com/question/2115716
#learnwithBrainly
I think the best answer would be letter B. Y= 20x and Y= 30x+120. So by calculating it through substitution you will come up to 20x = 30x+120. By simplifying the equation it will give you an answer of 12 days.
