7y=x+23
(x-2)^2+y^2 =25
2006-06-14 00:53:06 · 5 answers · asked by xavier h 1 in Science & Mathematics ➔ Mathematics
7y = x + 23
(x - 2)^2 + y^2 = 25
7y = x + 23
x = 7y - 23
(x - 2)^2 + y^2 = 25
((7y - 23) - 2)^2 + y^2 = 25
(7y - 23 - 2)^2 + y^2 = 25
(7y - 25)^2 + y^2 = 25
((7y - 25)(7y - 25)) + y^2 = 25
(49y^2 - 175y - 175y + 625) + y^2 = 25
49y^2 - 350y + 625 + y^2 = 25
50y^2 - 350y + 600 = 0
50(y^2 - 7y + 12) = 0
y^2 - 7y + 12 = 0
(y - 4)(y - 3) = 0
y = 4 or 3
x = 7y - 23
x = 7(4) - 23
x = 28 - 23
x = 5
or
x = 7(3) - 23
x = 21 - 23
x = -2
ANS : (3,-2) and (5,4)
2006-06-14 08:14:34 · answer #1 · answered by Sherman81 6 · 2⤊ 2⤋
7y = x + 23................a
(x-2)^2 + y^2 = 25 .....b
takingg equation b
x^2 + 4 - 4x + y^2 = 25 ...............(x-2)^2 is of the form (a - b)^2 = a^2 + b^2 - 2ab
=>x^2 + y^2 + 4x - 21 = 0...........c
now taking eqn a
7y = x + 23
=>x - 7y = -23 ..........d
now taking d and c
x - 7y = -23 * 4
x^2 + y^2 + 4x - 21
--------------------------
4x - 28y = - 92
x^2 + y^2 + 4x - 21 = 0 * minus sign
-----------------------------
-28y - x^2 - y^2 = 92
=> x^2 + y^2 + 28y + 92 = 0
=>x^2 + y(y + 28) + 92 = 0
2006-06-14 08:40:19 · answer #2 · answered by Anonymous · 0⤊ 0⤋
(-2, 3) and (5, 4)
2006-06-14 08:01:35 · answer #3 · answered by wIsEjEd1crack 1 · 0⤊ 0⤋
x-2+y=5
x=7-y
x=7y-23
7-y=7y-23
8y=30
y=30/8
x=7(30/8)-23
2006-06-14 08:01:34 · answer #4 · answered by scott_d_webb 3 · 0⤊ 0⤋
dude/dudette...watso ever it is but..it is a very long calculation....and the answer is(-2,3) and (4,5)
2006-06-14 08:09:58 · answer #5 · answered by sniper 3 · 0⤊ 0⤋