Let n = the unknown number
"The product of a number and 4" = 4 * n = 4n
"increased by 16" = + 16
Set it all equal to - 2.
4n + 16 = - 2
Subtract 16 from both sides to get constants on one side and variables on the other.
4n = - 2 - 16
Combine like terms:
4n = - 18
Divide both sides by 4 to isolate variable n.
n = - 18 / 4
= - 4 and 2/4 = - 4 and 1/2