5400-50.[84-[45-[7x-9]:2]]-10=2440 5400-50.[84-[45-7x+9:2]]-10=2440 5400-50.[84-[54-7x:2]]-10=2440 5400-50.[84-[27-7x]]-10=2440 5400-50.[84+27+7x]-10=2440 5400-50.[111+7x]-10=2440 5400-50.111+50.7x-10=2440 5400-5550+350x-10=2440 -150+350x-10=2440 -160+350x=2440 350x=2440+160 350x=2600 x=2600:350 x=7,4285