13 + {16 + 2 -[25 + 45) x 3] + 9}

-170

Concept:

When encountering questions that require multiple steps of the calculation, it is suggested to follow the PEMDAS.

Solve:

**Disclaimer** I assume that it is supposed to be (25 + 45). If it was, then you may refer to my answer. If the ")" after 45 is just a typo, you may point it out and I will redo it.

Given expression

 13 + {16 + 2 - [(25 + 45) × 3] + 9}

Do the parenthesis of the inner most

=13 + {16 + 2 - [70 × 3] + 9}

=13 + {16 + 2 - 210 + 9}

Do addition first, then subtraction

=13 + {18 - 210 + 9}

=13 + {27 - 210}

=13 - 183

=-170

Hope this helps!! :)

Please let me know if you have any questions

except a rational number. : )