Question

the equation of common tangent to circles x2+y2+14x-4y+28=0 and x2+y2-14x+4y-28=0​

Answer 1

Answer:

Step-by-step explanation:

x 2 + 14 x + y 2 − 4 y = 28

⇒ ( x + 7 ) 2 + ( y − 2 )2 = 28 + 49 + 4

⇒ ( x + 7 ) 2 + ( y − 2 ) 2 = 81 ←  in standard form

this is the equation of a circle with

centre  = ( − 7 , 2 ) and radius  =9

graph{((x+7)^2+(y-2)^2-81)=0 [-40, 40, -20, 20]}

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