Answer:
The value of x = 4 makes the given equation true.
Explanation:
Here we have to find what value of x, makes the given equation 49 -7x = 21 true.
To find the value of x, we need to solve for x.
49 - 7x = 21
Step 1: Isolate the variable and constant terms.
Subtract 49 from both sides, we get
-49 + 49 - 7x = 21 - 49
-7x = -28
Step 2: Divide both sides by -7, we get

x = 4
So, the value of x = 4 makes the given equation true.
Check
49 -7x = 21
Plug in x = 4
49 - 7(4) = 21
49 - 28 = 21
21 = 21
Which is true.