Question

Can someone help me with the first one pls

Answer 1

The answer of the first one is b

Explanation:

going left is negative and going up is positive

Answer 2

12. a

13a. (-3, 2)

13b.
`12√(2)`

13c.
`( x +3 )^2 + ( y - 2 )^2 = 288`

Explanation:

13a. Graph endpoints and find the center, and to find the center we can use the midpoint formula.

`midpoint = ((x_1+x_2)/(2),(y_1+y_2)/(2))\\ = ((-9+3)/(2),(-4+8)/(2))\\= ((-6)/(2),(4)/(2))\\ = (-3,2)`

13b. Use given points and use distance formula to find radius.

`distance = \sqrt{({x_2-x_1})^2+({y_2-y_1})^2}\\= \sqrt{({3-(-9)})^2+({8-(-4)})^2}\\= \sqrt{({3+9})^2+({8+4})^2}\\=\sqrt{({12})^2+({12})^2}\\ =\sqrt{({12})^2+({12})^2}\\= √(144+144) = √(288) = 12√(2)`

13c. Refer back to 13a and 13b to setup the equation of the circle.

`( x - h )^2 + ( y - k )^2 = r^2\\( x - (-3) )^2 + ( y - 2 )^2 = (12√(2))^2\\( x +3 )^2 + ( y - 2 )^2 = 288`

Sorry if it looks long but I hope that helps!