শ্রেণি সপ্তম, বীজগণিতীয় রাশির সরল

Question

Answer 1

1. 13-7[-5+2(-3-8)+{-3+(-5-8)}]

= 13-7[-5+2*(-11)+{-3+(-13)}]

= 13-7[-5-22+{-3-13}]

= 13-7[-5-22-16]

= 13-7[-43]

= 13+301

= 314

2. 13a-11b+5[-a+2b-{-5c+(2a-15b)}]

= 13a-11b+5[-a+2b-{-5c+2a-15b}]

= 13a-11b+5[-a+2b+5c-2a+15b]

= 13a-11b+5[-3a+17b+5c]

= 13a-11b-15a+85b+25c

= -2a+74b+25c

3. 5x²+7y²-9z²+3[11x²-2y²+{(5x²-19z²)+23y²}] 

= 5x²+7y²-9z²+3[11x²-2y²+{5x²-19z²+23y²}] 

= 5x²+7y²-9z²+3[11x²-2y²+5x²-19z²+23y²]

= 5x²+7y²-9z²+3[16x²+21y²-19z²]

= 5x²+7y²-9z²+48x²+63y²-57z²

= 53x²+70y²-66z²