3 because 7*3=21,...........
30/16=15/8...............
Answer:


The equations have the same slope but different y-intercepts. This means the lines are parallel and there is no solution (since they do not intersect).
Before we get started, it is good to remember PEMDAS - the acronym that tells you the order to carry out equations.
P = parentheses
E = exponents
M = multiplication
D = division
A = addition
S = subtraction
Knowing this, we should start by doing the equations <em>within </em>each parentheses.

So we did the addition and subtraction pieces within each group leaving us with the above equation. Now let's multiply:

20 is the answer.
Answer:
Step-by-step explanation:
If you factor the expression 7a+21 you can get:
7 × (a+3)