The sum of three times a greater integer and 5 times a lesser integer is 9. Three less than the greater equivalent the lesser. What is the value of the lesser integer?
Let x = the lesser integer and let y = the greater integer. The ?rst sentence in the question provides the equation 3y + 5x = 9. The second sentence provides the equation y - 3 = x. Substitute y - 3 for x in the second equation: 3y + 5(y - 3) = 9. Use the distributive property on the left side of the equation: 3y + 5y - 15 = 9. Combine such as terms on the left side: 8y - 15 = 9; add 15 to both sides of the equation: 8y - 15 + 15 = 9 + 15. Simplify to: 8y = 24. Divide both sides of the equation by 8: 8y/8 =24/8.
This provides a solution of y = 3. Therefore the lesser, x, is three less than y, so x = 0.