Answer:
Step-by-step explanation:
hello :
x2+y2+16y−30x=0 means : (x²-30x)+(y²+16y) =0
(x²-30x+15²)-15²+(y²+16y+8²) -8²=0
(x-15)²-225+(y+8)²-64=0
(x-15)²+(y+8)²=289=17²......standard form when the center is (15,- 8)
and radius 17
36
2(k-5)+3k=k+6
-3k. -3k
2(k-5)=-2k+6
/2. /2
k-5=-k+3
+k. +k
2k-5=3
+5. +5
2k=8
k=4
if the diameter is 20, the its radius must be half that or 10.
