I will give you an example of a whole number that we can rename easily.
253 can be represented as:
253 ones2 hundreds 5 tens 3 ones
2 hundreds 53 ones25 tens 3 ones
<span>Sam had to substitute 100 instead of X
</span><span>5x+3x+20 =
8x + 20 =
8*100 + 20 =
800 + 20 =
820 </span>← answer
52 + (-77) =
52 - 77 = -25
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52 - (-77) =
52 + 77 = 129
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your answer is: 52 - (-77)
