Which best explains why the equation 7x + 3 = 7x + 3 has infinitely many
solutions?

because no matter what x is, the equation on both sides are the same

Step-by-step explanation: for example we will replace x with 5

7(5) + 3=7(5) + 3

7 times 5 equals 15, plus 3 equals 18, now lets look at the other side, 7 times 5 equals 15, plus 3 equals 18, there fore u could use the number 777,777,777 and you would get the same answer on both sides

-7

step-by-step explanation:

x^2 + 18x + 74 = (x + 9)^2 - 81 + 74

= (x + 9)^2 - 7.

so q = -7.