Only need part A and C trying to use approach of xt m0 t t0

Only need part A and C.

trying to use approach of:
x(t)= m₀[ t- t₀] u( t-t₀) - m₀[ t-t₁] u( t-t₁) + m₁[ t-t₁] u( t-t₁) = m₀[ t- t₀] u( t-t₀) + [ m₁- m₀] [ t-t₁] u( t-t₁) ; t < t₂

Solution