Andrei si mihai cantaresc impreuna 76 kg, mihai si rares cantaresc impreuna 78 kg, iar andrei si rares cantaresc impreuna 82 kg. cate kg cantareste fiecare?

A+m=76 

De mai jos scoatem pe a si m in functie de r

m+r=78 => m=78-r

a+r=82 => a=82-r

Inlocuim in prima

82-r+78-r=76

160-2r=76

-2r=76-160

-2r=-84 / -1 pt a scapa de -

2r=84

r=84:2

r=42 ani

De acum e simplu, inlocuim mai sus

m=78-r

m=78-42=36

a=82-42=40

- 2 + 10x³ - 21x² + 19x - 4

step-by-step explanation:

each term in the second factor is multiplied by each term in the first factor

x²(- 2x² + 4x - 1) - 3x(- 2x² + 4x - 1) + 4(- 2x² + 4x - 1) ← distribute

= - 2 + 4x³ - x² + 6x³ - 12x² + 3x -8x² + 16x - 4

collect like terms

= - 2 + 10x³ - 21x² + 19x - 4 ← in standard form

answer: plz give a pic and answer choices so i can answer!

step-by-step explanation: