Jawaban:

1) x² + y² = r²

x² + y² = 40

r² = 40

r = √40

r √4 x √10

r = 2√10

2) x² + y² + 12x - 8y - 12 = 0

titik pusat

( -½ x 12) (- ½ x 8)

titik pusat ( -6, -4)

r = √x² + y²

r = √6² + 4²

r = √36 + 16

r = √52

r = √ 4 x 13

r = 2√13

3) titik pusat ( 8,-5)

r = 4√2

(x -a)² + ( y - b )² = r²

( x - 8)² + (y - (-5))² = (4√2)²

x² - 16x + 64 + y² + 10y + 25 = 16 x 2

x² + y ² -16x + 10y + 64 + 25 - 32 = 0

x² + y² - 16x + 10 + 57 = 0

4) x² + y² = 32 titik ( -7, 3)

x² + y² = r²

x² + y² = 32

r² = 32

r = √32

r = √16 x 2

r = 4√2

(x -a)² + ( y - b )² = r²

( x -(-7)² + ( y - 3)² = (4√2)²

( x + 7)² + ( y -3)² = 32

x² - 14x + 49 + y² - 6y + 9 -32 = 0

x² + y² - 14x -6y - 26 = 0

5) p² = l² - ( r1 - r2)²

14² = l² - ( 2 - 4)²

196 = l² - (-2)²

196 = l² - 4

l² = 196 + 2

l = √198

l = 14,07 cm

6) p² = d² - ( r1 + r2)²

16² = d² - ( 8 + 4)²

16² = d² - 12²

256 = d² - 144

d² = 256 + 144

d = √400.

d = 20 cm

Semoga membantu dan tidak keliru