Question

Se da ca 3x + 3y + 12 = 30 si a = 17 . Calculati [100-(x+y)]+3a

Answer 1

dam factor comun pe 3

3(x+y)+12= 30

3(x+y) = 30-12

3(x+y) = 18

x+y= 18:3

x+y = 6

[100-(x+y)]+3a= [100-6]+3*17 = 94+51 = 145

Answer 2

3x + 3y + 12 = 30

a = 17

----------------------------/

[ 100 - ( x + y ) ] +3a = ?

----------------------------/

3x + 3y + 12 = 30

3 ( x + y ) = 30 - 12

3 ( x + y ) = 18

x + y = 18 : 3

x + y = 6

⇒ [ 100 - ( x + y ) ] +3a  = ( 100 - 6 ) + 3 · 17 = 94 + 51 = 145