A system does $1\mathrm{.}40{10}^{8}J$ of work while $8\mathrm{.}50{10}^{8}J$ of heat transfer occurs to the environment. What is the change in internal energy $($in J$)$ of the system assuming no other changes $($such as in temperature or by the addition of fuel$)?($Indicate if this is a positive or negative value$).$