It all depends on the math question but usually you solve for x, then check it. Plug x back in and see if it works. But it all depends on the math problem
Answer:

Step-by-step explanation:
The first step to solving this problem is verifying if this sequence is an arithmetic sequence or a geometric sequence.
This sequence is arithmetic if:

We have that:




This is not an arithmetic sequence.
This sequence is geometric if:




This is a geometric sequence, in which:
The first term is 40, so 
The common ratio is
, so
.
We have that:

The 10th term is
. So:



Simplifying by 4, we have:

Gallons of gas needed = 220/23 = 9.565 gallons
Amount of money spent on gas = $2.35 x 9.565 = $22.48
Answer:
yes
Step-by-step explanation:
50x513 is 25,650, 25,650x2 is 51,300