1=(7/w)-(10/(w^2))

Solution for 1=(7/w)-(10/(w^2)) equation:

D( w )

w^2 = 0

w = 0

w^2 = 0

w^2 = 0

1*w^2 = 0 // : 1

w^2 = 0

w = 0

w = 0

w = 0

w in (-oo:0) U (0:+oo)

1 = 7/w-(10/(w^2)) // - 7/w-(10/(w^2))

10/(w^2)-(7/w)+1 = 0

10/(w^2)-7*w^-1+1 = 0

10*w^-2-7*w^-1+1 = 0

t_1 = w^-1

10*t_1^2-7*t_1^1+1 = 0

10*t_1^2-7*t_1+1 = 0

DELTA = (-7)^2-(1*4*10)

DELTA = 9

DELTA > 0

t_1 = (9^(1/2)+7)/(2*10) or t_1 = (7-9^(1/2))/(2*10)

t_1 = 1/2 or t_1 = 1/5

t_1 = 1/5

w^-1-1/5 = 0

1*w^-1 = 1/5 // : 1

w^-1 = 1/5

-1 < 0

1/(w^1) = 1/5 // * w^1

1 = 1/5*w^1 // : 1/5

5 = w^1

w = 5

t_1 = 1/2

w^-1-1/2 = 0

1*w^-1 = 1/2 // : 1

w^-1 = 1/2

-1 < 0

1/(w^1) = 1/2 // * w^1

1 = 1/2*w^1 // : 1/2

2 = w^1

w = 2

w in { 5, 2 }