Verify that `x sgnx=|x|`; `|x|sgnx=x`; `x(sgnx)(sgnx)=x`

Verify that -(-x)=x , when : x=7/19

Verify that x=4 is a root of the squation 2x-3=5

Verify that x=4 is a root of the equation 2x-3=5

Verify that x=3 is the solution of the equation 2x-3=3

Verify that (-x) is the as x for (i) x=(13)/(17) (ii) x=(-21)/(31)

Verify that x=8 is a solution of the equation (5x-4)/(8)-(x-3)/(5)=(x+6)/(5)

Verify -(-x)=x for x=(3)/(5)

verify that int(2x-1)/(2x+3)dx = x - log|(2x+3)^(2)|+C

Verify that 5, -2 and 1/3 are the zeros of the cubic polynomial p(x) = 3x^(3) - 10x^(2) - 27x+10 and verify the relation between its zeros and coefficients.

Verify that int(2x+3)/(x^(2)+3x)dx = log|x^(2)+3x|+c