Question

1)3(28а+ b)-73a+8b при а+b=7 2)3m+35n+8(3m-n) при m+n=4

Answer 1

3(28а+б)-73а+8б=84а+3б-73а+8б=11а+11б=11(а+б)=11×7=77;при а+б=7

3m+35n+8(3m-n)=3m+35n+24m-8n=27m+27n=27(m+n)=27×4=108;при m+n=4