On exponential stability of linear differential equations with several delays

New explicit conditions of exponential stability are obtained for the nonautonomous linear equationx˙(t)+∑k=1mak(t)x(hk(t))=0, where ∑k=1mak(t)⩾0, hk(t)⩽thk(t)⩽t, in particular, for equations with positive and negative coefficients. We apply the comparison method based on the Bohl–Perron type theorem. Exponentially stable delay equations with a positive fundamental function are used for comparison.