Question

Folosind proprietatile inmultirii numerelor rationale,calculati:
a)(3/5•2/7)•21/18;
b)3/5•(2/7•21/18);
c)3/5•2/7•21/18;
d)(2/7•4/3)•(3/2•1/5);
e)2/7•(4/3•3/2)•1/5;
f)2/7•4/3•3/2•1/5;

Answer 1

a)(3/5×2/7)×21/18= 10/35×21/18⇒210/630 simplificam cu 210 ⇒1/3
b)3/5×(2/7×21/18)=3/5×42/36⇒126/180 simplificam cu 6 ⇒ 21/30 mai simplificam cu 3 ⇒ 7/10
c)3/5×2/7×21/18=6/35×21/18⇒126/630 simplificam cu 3 ⇒42/210 mai simplificam cu 7 ⇒ 6/30 mai simplificam cu 3 ⇒2/10
d)(2/7×4/3)×(3/2×1/5)=8/21×4/10⇒24/210 simplificam cu 3⇒8/70 simplificam cu 2⇒4/35
e)2/7×(4/3×3/2)×1/5=2/7×12/6×1/5⇒24/42×1/5⇒24/210 simplificam cu 6⇒4/35
f) 2/7×4/3×3/2×1/5=8/21×3/10=24/210 simplificam cu 6 ⇒4/35