Question

Daca a si b sunt numere naturale asfel incat 3×a+2×b=2020,calculeaza.
A) 6×a+4×b
B) 9×a+4×b
C) 12×a+9+8×b

Answer 1

3a +2b =2020

a) [3a + 2b = 2020] × 2

6a + 4b = 4040

b) 9 × a + 6 × b = ?

[3a + 2b = 2020] × 3 ⇒ 9a + 6b = 6060

c) 12 × a + 9 + 8 × b =?

[3a + 2b = 2020] × 4⇒ 12a + 8b = 8080

12a + 9 + 8b =(12a + 8b) + 9 = 8080 + 9 = 8089