How the answer comes in minus of 30 z - Maths - Algebraic Expessions and Operations on them

Question

How the answer comes in minus of 30 z

Alok Kumar · Accepted Answer

Dear student,
<img alt="" src=
"https://s3mn%20mnimgs%20com/img/shared/content_ck_images/ck_616071b9241df%20jpg"
style="width: 1023px; height: 538px;">
Regards