Question

Stiind ca x+2×y=24si x×y=19, determinati y. Stiind ca 3×x+2×y=17si 2×x+2×y=13 , determinati x. stiind ca x+2×y+z=17 si x+y =10, determinati y+z.

Answer 1

x + 2 y = 24   si   x + y = 19

x + y + y = 24

19 + y = 24

y = 24 - 19

y = 5

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3 x + 2 y = 17   si    2 x + 2 y = 13

x + 2 x + 2 y = 17

x + 13 = 17

x = 17 - 13

x = 4

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x + 2 y + z = 17    si   x + y = 10

( x + y ) + ( y + z ) = 17

10 + ( y + z ) = 17

y + z = 17 - 10

y + z = 7