Label your numbers (I'm picking x and y) x+y=35 2x=5y find the relationship between your numbers x=35-y apply this to the other equation 2 (35-y)=5y now simplify to find y 70-2y=5y 70=7y y=70/7=10 now apply your newly found y to find x x+10=35 x=25 check your answers 2 (25)=5 (10) 50=50 so our first number x is 25 and our second number y is 10