9/y+2-5/y-2=4/y^2-4
2007-11-20 01:37:38 · 4 answers · asked by ann m 1 in Science & Mathematics ➔ Mathematics
y^2-4 is actually (y-2)(y+2)
multiply (y-2)(y+2) on both sides to eliminate all denominator
you get
9(y-2)-5(y+2)=4
9y-18-5y-10=4
4y=32
y=8
2007-11-20 01:41:01 · answer #1 · answered by someone else 7 · 0⤊ 0⤋
Ans:
4 / y ^ 2 - 4 = 4 / y ^ -2
= 4 * y^2
9 / y + 2 - 5 / y - 2 is 9 / y - 5 / y + 2 - 2 = 4 / y
Therefore 4 / y = 4 * y ^ 2
Multiply both sides by y we get
4 = 4 * y ^ 3
y^ 3 = 1
y = cuberoot(1)= 1
2007-11-20 01:53:34 · answer #2 · answered by Anonymous · 0⤊ 0⤋
9/y+2-5/y-2=4 /y^2-4
lcd = y-2 y+2
9(y-2)-5(y+2)=4
9y-18-5y+10=4
4y-8=4
4y-8+8=4+8
4y=12
y=3
2007-11-20 02:57:31 · answer #3 · answered by Dave aka Spider Monkey 7 · 0⤊ 0⤋
9/(y+2)-5/(y-2)=4/(y^2-4)
{9(y-2)-5(y+2)}/(y-2)(y+2)=4/(y-2)(y+2)
(9y-18-5y-10)/(y-2)(y+2)=4/(y-2)(y+2)
now excluding (y-2)(y+2) from both side,
(9y-18-5y-10)=4
4y-28=4
4y=32
y=8 ans.
2007-11-20 01:51:51 · answer #4 · answered by dinesh320 2 · 0⤊ 0⤋