Answer:
-212800
Step-by-step explanation:
7.2 × 10³ = 7.2 × 1000 = 7200
2.2 × 10 to the power 5 = 2.2 × 100000 = 220000
7200 - 220000 = -212800
The first one is the answer to the first question.
the second one is the answer to the second question
We could do it with algebra. But we can also do it the long way, which is
shorter than the algebraic way.
The digit in the tens place is 3 times the digit in the units place.
So the number MUST be
31, or
62, or
93 .
It can't be anything else.
Now here they are again, with the reverse of each one:
31 . . . 13 The new number is 18 less.
62 . . . 26 The new number is 36 less.
93 . . . 39 The new number is 54 less.
Obviously, the original number is 62.
