Question

calculeaza : ab+ac+70=170 şi ab-ac-48=2
DAU COROANA SI 21 PUNCTE!

Answer 1

ab + ac + 70 = 170
ab + ac = 170 - 70
ab + ac = 100
ab - ac - 48 = 2
ab - ac = 48 + 2
ab - ac = 50
ab + ac = 100
le adunam
2ab = 150
ab = 150 : 2
ab = 75
le scadem
- 2ac = - 50
ac = 50 : 2
ac = 25
75 + 25 + 70 = 170
170 = 170
75 - 25 - 48 = 2
75 - 73 = 2
2 = 2

Answer 2

ab + ac + 70 = 170
ab + ac = 170 - 70
ab + ac = 100 ( 1 )

ab - ac - 48 = 2
ab - ac = 2 + 48
ab - ac = 50 ( 2 )

(1) + (2) ==> 2×ab = 100 + 50 ==>
==> 2×ab = 150
ab= 150 : 2
ab = 75

ac = 100 - 75
ac = 25

ab = 75
ac = 25

Verificare:
75 + 25 + 70 = 100 + 70 = 170
75 - 25 - 48 = 50 - 48 = 2