Here is another: 2 + |3x + 15| > 8 subtract 2 -2 -2 |3x + 15| > 6 3x + 15 must be bigger than 6 or smaller than -6. 3x + 15 > 6 3x + 15 < - 6 -15 -15 subtract 15 -15 -15 3x > -9 3x < -21 3 3 divide by 3 3 3 x > -3 or x < -7 Check with 0! Check with -10! 2 + |3(0) + 15| > 8 2 + |3(-10) + 15| > 8 2 + |0 + 15| > 8 2 + | -30 + 15| > 8 2 + |15| > 8 2 + |-15|> 8 2 + 15 > 8 2 + 15 > 8 17 > 8 True! 17 > 8
Here is another: 2 + |3x + 15| > 8 subtract 2 -2 -2 |3x + 15| > 6 3x + 15 must be bigger than 6 or smaller than -6. 3x + 15 > 6 3x + 15 < - 6 -15 -15 subtract 15 -15 -15 3x > -9 3x < -21 3 3 divide by 3 3 3 x > -3 or x < -7 Check with 0! Check with -10! 2 + |3(0) + 15| > 8 2 + |3(-10) + 15| > 8 2 + |0 + 15| > 8 2 + | -30 + 15| > 8 2 + |15| > 8 2 + |-15|> 8 2 + 15 > 8 2 + 15 > 8 17 > 8 True! 17 > 8