Question

Daca x + 2y = 17 si y - 3z = 4 Atunci calculati

a) 2x+5y-3z
b)(3x+6y)+(2y-6z)
c)(2x+4y)x(x+4y-6z)

Va rog!

Answer 1

a) x+2y = 17
2(x+2y) = 2*17
2x+4y = 34
2x+4y+y-3z = 34+4
2x+5y-3z = 38

b) x+2y = 17
3(x+2y) = 3*17
3x+6y = 51
y-3z = 4
2(y-3z) = 2*4
2y-6z = 8
(3x+6y)+(2y-6z)=51+8=59

c) 2x+4y = 34
x+4y-6z = x+2y + 2y-6z = 17+8 = 25
34*25 = 850

Answer 2

a) x+2y=17 |×2
2x + 4y=34
y-3x= 4
------------------- ( adunam cele două relatii)
2x+5y-3z=38

b)x+2y=17 |×3
y-3z=4|×2

3x+ 6y= 51
2y-6z=8
----------------(adunam cele două relatii)
(3x+6y)+(2y-6z)=59

c)y-3z=4 |×2
2y-6z=8
x+2y=17
--------------( adunam cele două relatii)
x+4y-6z=25

x+2y=17|×2
2x+4y=34
x+3y-6z=25
-------------------( inmultim cele două relatii)
(2x+4y) × (x+3y-6z) =34×25=850


Sper ca te am ajutat!!!!