I need help on my math
the problem is
[x^(-2) - y^(-2)]/[x^(-1)+y^(-1)] and i'm suppose to simplify the fractional expression. the answer is (y-x)/(xy). how do i get that answer?
2007-09-03 16:31:06 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
[x^(-2) - y^(-2)] / [x^(-1)+y^(-1)]
multiply the numerator and denominator by x^(-1) - y^(-1)
[(x^(-2) - y^(-2)) * (x^(-1) - y^(-1)) ] / [x^(-2) - y^(-2)]
simplify
x^(-1) - y^(-1) = 1/x - 1/y
1/x * y/y - 1/y * x/x = (y - x) / (xy)
2007-09-03 16:46:25 · answer #1 · answered by Merlyn 7 · 0⤊ 0⤋
Multiply top and bottom by x^(2) * y^(2)
=> [y^(2) - x^(2)]/xy[x^(1)+y^(1)] = (y - x)*(y + x)/xy(y + x)
simplify => (y - x)/xy
2007-09-03 23:45:15 · answer #2 · answered by Beardo 7 · 0⤊ 0⤋
[x^(-2) - y^(-2)]/[x^(-1)+y^(-1)] =
[ x+y ] / [ x^2 - y^2] =
[ x+y] / [ (x-y) (x+y) ] =
1 / (x-y)
thats my answer
2007-09-03 23:39:21 · answer #3 · answered by esc 2 · 1⤊ 1⤋
[x^(-2) - y^(-2)]/[x^(-1)+y^(-1)]
=[y^(2)-x^(2)]/[xy^2+yx^2]
=[(y-x)(y+x)]/[xy(y+x)]
=(y-x)/(xy)
2007-09-03 23:44:25 · answer #4 · answered by jili 1 · 0⤊ 0⤋