Answer:
By plotting in the number in the equation (aka where all the x’s are variables are) and seeing if it works.
Explanation:
For example, let’s use the problem:
3x + 4 = 16
if the given number is 4, we fill it in for x-
3 (4) + 4= 16
solve to see if true:
12 + 4 = 16
16 = 16
hence, the given number 4 makes the equation true!
hopes this helps, have a great day :)