Answer:
1. 30°
2.90°
3. 12 units
Step-by-step explanation:
I can't believe there's nothing confirming that this is a parallelogram/a rhombus?! Assuming is awful, and I wish you could say you can't know for sure lol but for the sake of this answer, let's just call it a rhombus. (There was probably some context elsewhere that you didn't put over here, hopefully.)
1.
The reason I say this is: in a rhombus, the diagonals bisect the angles. This means that the diagonals split the angles they meet into two equal parts. That way, it would make sense. m∠QPR=m∠SPR=30°.
2.
If it is a rhombus, the diagonals are perpendicular to each other, so m∠QTP should be 90°.
3.
Diagnonals in a rhombus (and in any parallelogram) bisect each other, so PT=TR=6, and RP=PT+TR=12 units.
Sorry if this is all dreadfully wrong, and I hope I helped you!
I will explain you and pair two of the equations as an example to you. Then, you must pair the others.
1) Two circles are concentric if they have the same center and different radii.
2) The equation of a circle with center xc, yc, and radius r is:
(x - xc)^2 + (y - yc)^2 = r^2.
So, if you have that equation you can inmediately tell the coordinates of the center and the radius of the circle.
3) You can transform the equations given in your picture to the form (x -xc)^2 + (y -yc)^2 = r2 by completing squares.
Example:
Equation: 3x^2 + 3y^2 + 12x - 6y - 21 = 0
rearrange: 3x^2 + 12x + 3y^2 - 6y = 21
extract common factor 3: 3 (x^2 + 4x) + 3(y^2 -2y) = 3*7
=> (x^2 + 4x) + (y^2 - 2y) = 7
complete squares: (x + 2)^2 - 4 + (y - 1)^2 - 1 = 7
=> (x + 2)^2 + (y - 1)^2 = 12 => center = (-2,1), r = √12.
equation: 4x^2 + 4y^2 + 16x - 8y - 308 = 0
rearrange: 4x^2 + 16x + 4y^2 - 8y = 308
common factor 4: 4 (x^2 + 4x) + 4(y^2 -8y) = 4*77
=> (x^2 + 4x) + (y^2 - 2y) = 77
complete squares: (x + 2)^2 - 4 + (y - 1)^2 - 1 = 77
=> (x + 2)^2 + (y - 1)^2 = 82 => center = (-2,1), r = √82
Therefore, you conclude that these two circumferences have the same center and differet r, so they are concentric.
The answer to the problem is D
Answer:
4 packs of invitations and 2 packs of napkins.
Step-by-step explanation: