They give you a couple hints. Take what you know first: x + y = 72. Two numbers, x and y, and they add to 72. You also know one more thing: They tell you that 5 times one of the numbers, minus 8, equals the other number! There is your hint! So how about we do this: x+y=72 and 5y-8=x. So now, all you do is substitute your new term for x into the original equation (5y-8)+y = 72. Or...6y-8=72. Or...6y=80. That means y = 13.33 (we will do a decimal here instead of a fraction because its easier for me. But 13.33 is really 13 1/3, OK? So round to the nearest third) And if y=13.33, then x must equal 58.67 (which is really 58 2/3). But youre not done yet! Now, cross check the answer: Does, in fact one number equal 8 less than 5 times the other number? Does it? Lets check. 13.33 *5 = 66.66. And 66.66-8 = 58.66. Remember, instead of fractions, I used decimals to type in here. But..the answer is in the beauty of substitution! Hope that helps.
