Part A: Substitute/plug in each number into the equation to see which number will make the equation true.
x + 7 = 16 Plug in 5 into "x"
5 + 7 = 16
12 = 16 5 doesn't make the equation true because it equals 12 not 16
x + 7 = 16 Plug in 7 into "x"
7 + 7 = 16
14 = 16 7 doesn't make the equation true because it equals 14 not 16
x + 7 = 16 Plug in 9 into "x"
9 + 7 = 16
16 = 16 9 makes the equation true because it equals 16
Part B: Plug in 9 into "x" in the inequality to see if it still makes it true.
x + 7 < 16 [x plus 7 is less than 16]
9 + 7 < 16
16 < 16 [16 is less than 16] The same number would not make the inequality true because 16 can't be less than itself.
To figure out which numbers satisfy the inequality, plug it into the inequality:
x + 7 < 16 Plug in 5 into "x"
5 + 7 < 16
12 < 16 5 does satisfy the inequality because 12 is less than 16
x + 7 < 16 Plug in 7 into "x"
14 < 16 7 does satisfy the inequality because 14 is less than 16
x + 7 < 16 Plug in 11 into "x"
11 + 7 < 16
18 < 16 11 doesn't satisfy the inequality because 18 isn't less than 16
