Tom has saved $128, and his goal is $500. how much more must he save.

a) x + 128 = 500
b) x - 128 = 500
c) x + 500 = 128
d) x - 500 =128

in other words, what number, added to 128, gives 500?

To find out how much more Tom needs to save to reach his goal of $500, we can subtract the amount he has saved ($128) from the goal amount ($500).

Therefore, the correct equation would be:

x = 500 - 128

Simplifying the equation:

x = 372

So, Tom must save $372 more to reach his goal.

Therefore, the correct option is:

a) x + 128 = 500

To determine how much more Tom must save to reach his goal of $500, we need to perform a subtraction operation.

We subtract the amount Tom has already saved ($128) from his goal amount ($500) to find the difference.

$500 - $128 = $372

Therefore, the correct answer is:
d) x - 500 = 128

its C