Write each sentence using mathematical symbols:

(a) The sum of $7$ and $x$ is $-7$:

(b) Two less than the product of $4$ and $d$ is $-12$:

Note: The middle answer blank in both parts is for you to enter "$<$=", "$<$", "=", "$>$", or "$>$=" for "less than or equal to", "less than", "equals", "greater than", or "greater than or equal to", respectively.