61. लोहे से बने एक ठोस सम प्रिज्म में 5 सेमी, 10 सेमी एवं 13 सेमी भुजाओं वाले त्रिभुज की
अनुप्रस्थ काट है एवं इसकी ऊँचाई 10 सेमी है।
यदि लोहे के एक घन सेमी का वजन 7 ग्राम है, तो
प्रिज्म का वजन (लगभग) कितना होगा?​

step by step explanation: when u removing the parentheses and combined them that would be : x+3y-x-y=2y

answers

\3. yes the presentation (i.e. odd numbers being written as differences of two squares) is possible for all odd natural number however the presentation may not be unique. for example,  57=112−82=292−28257=112−82=292−282.

\4. 2 can't be written as a difference of two squares because 4-1=3 and 1-1=0 and the difference of squares grows to integers larger that 3.

can i get some in proving questions 1 and 2?