Question

Ştiind că a+b=32 şi b+c=45,calculati va rog valorile numerelor:
a) 2a+5b+3c; b) a+5b+4c; c) 3a+7b+4c.

Answer 1

a+b=32 b+c=45 A)2a+5b+3c=2a+2b+3b+3c=2 (a+b)+3 (b+c)= 2×32+3×45=64+135=199 B)a+5b+4c=a+b+4b+4c=a+b+4 (a+b)=32+4×45= 32+180=212 C)3a+7b+4c=3a+3b+4b+4c=3(a+b)+4 (b+c)= 3×32+4×45=96+180=276