Question

Solve the system.

3x2 - 2y2 = -5
x2 + y2 = 25
A. (3, 4), (3, -4), (-3, 4), (-3, -4)
B. (4, 4), (5, 4), (3, -4), (1, –4)
C. (-3, 4), (1, 4), (-3, -4), (2, -4)
D. (1, 4), (2, –4), (–4, 3), (–3, –3)



Find the coordinates of the corner points using the following:

x - y = -2
2x + y = -1
x = -2
A. (-2, 0)
B. (-2, 0), (-1, 1)
C. (-2, 0), (-1, 1), (-2, 3)
D. (-1, 1), (-2, 3)

Answer 1

i choose 1. b
2. C

Answer 2

#1 and did you actually try using your choices to see whether they worked?

You know that if ((x,y) is a solution, so is (-x,-y) since both x^2 and y^2 are the same value whether x,y are positive or negative.

Double eq #2 and add it to eq #1 to get 5x^2 = 45, so x^2 = 9.

So, x = ±3
Then, thinking back to the good ole 3-4-5 right triangle, you can see that y= ±4.

So, (A) is the answer.

#2. correct

Answer 3

thank you