Question

daca x=3si a+b =9 ,calculati 2a+2b+2x = ; b)10x -(2a+2b)= ; c)x+8a +8b =; d)xa+xb= ; e (3a +3b-2x) .(2a+2b -3x ) =

Answer 1

a) 2a+2b+2x=2(a+b)+2x=2*9+2*3=18+6=24

b) 10x-(2a+2b)=10*3-2(a+b)=30-2*9=30-18=12

c) x+8a+8b=x+8(a+b)=3+8*9=3+72=75

d) xa+xb=x(a+b)=3*9=27

e) (3a+3b-2x)* (2a+2b-3x)=[3(a+b)-2*3]*[2(a+b)-3*3]=(3*9-2*3)*(2*9-9)=(27-6)*(18-9)=21*9=189