Question

Calculati:
ab+ac, stiind ca b+c=50 si a =2.
ab - ac, stiind ca a =7 si b-c=100.
xy+xz+15,stiind ca x=9 si y+z=11.
5xy + 5xz+21,stiind ca x =4 si y+z=100.​

Answer 1

1. ab + ac = ?

b+c = 50

a= 2

ab + ac = a*(b+c) = 2 * 50 = 100

2. ab - ac

a = 7

b - c = 100

ab - ac = a*(b-c) = 7*100 = 700

3. xy + xz + 15 = ?

x = 9

y + z = 100

xy + xz + 15 = x*(y+z) + 15 = 9*100+15 = 915

5xy + 5xz + 21

x = 4

y + z = 100

5xy + 5xz + 21 = 5x(y+z) + 21 =

20*100 + 21 = 2021