Question

URGENT!!!!!!EXERCITIUL 5!VA ROG RAPID!!DAU COROANA SI 15 PUNCTE

Answer 1

a) ab + ac = 520  si b + c = 52 
a(b+c) = 520⇒a × 52 = 520⇒a = 520:52⇒a = 10

b)ab - ac = 45,  b - c = 9
a × (b - c) = 45⇒a × 9 = 45⇒a = 45:9 ⇒ a = 5

c) b+c=?
ab + ac + 70 = 170  si a = 25

a(b + c) = 170 - 70⇒ 25 × (b + c) = 100⇒(b + c) = 100:25⇒(b + c) = 4

d)
b - c=?
ab - ac - 48 = 2  si a = 10

a(b - c) - 48 = 2 ⇒ 10 × (b - c) = 2 + 48 ⇒(b - c) = 50:10⇒ (b - c) = 5