A whole number is 6 more than 2 times another number. The sum of the two numbers is less than 50. This can be written in an inequality as x + 2x + 6 < 50, where x represents the smaller number. From the set {13, 14, 15, 16, 17}, the values of x for which the inequality holds true are .

First, you have to simplify the inequality and solve for x.

x + 2x + 6 < 50

3x + 6 < 50

3x < 44

x < 14 2/3

So, you now have another set of numbers, {13, 14, 15, 16, 17}, and you know x must be smaller than 14 2/3. The only two numbers in that set that works are 13 and 14, making A: {13, 14} the correct answer. 

because linear equations are a lot simpler than quadratics equations, and linear equations formula is a lot easier to memorize. that's why i think they're harder.

x/3-10=8

x/3=18

x=48