Question

Daca a=$\frac{5}{6}$ , b+c=$\frac{7}{20}$ si c-d=$\frac{1}{24}$ , calculati a*b+2*a*c-a*d.

Answer 1

$ab+2ac-ad=ab+ac+ac-ad=a(b+c)+a(c-d)=\\=\displaystyle\frac{5}{6}\cdot\frac{7}{20}+\frac{5}{6}\cdot\frac{1}{24}=\frac{7}{24}+\frac{5}{144}=\frac{47}{144}$

Answer 2

ab +2ac-ad= ab+ac+ac-ad=a(b+c)+a(c-d)= 5/6 * 7/20 + 5/6 *1/24=7/24 + 5/144=

=(42+5)/144= 47/144