Question

la 3,4,5 VA ROG DAU COROANA!!!!!​

Answer 1

Răspuns:

3.

9a+9b=9(a+b)=9×65=585

4.

ax-bx=x(a-b)=17×25=425

5.

ab+ac=a(b+c)=30

a×6=30--->a=30/6

a=5

Answer 2

Explicație pas cu pas:

$3 + 6 + 9 + ... + 297 + 300 = 3 \cdot (1 + 2 + 3 + ... + 99 + 100) = 3 \cdot \dfrac{100 \cdot (100 + 1)}{2} = 3 \cdot \dfrac{100 \cdot 101}{2} = 3 \cdot 5050 = \bf 15150$

$9a + 9b = 9 \cdot (a + b) = 9 \cdot 65 = \bf 585$

$ax - bx = x \cdot (a - b) = 17 \cdot 25 = \bf 425$

$ab + ac = 30 \iff a \cdot (b + c) = 30 \\ a \cdot 6 = 30 \iff a = 30 : 6 \implies \bf a = 5$