Question

Ex 14! COROANA!!!!!!!!

Answer 1

14a)

8x=3y => y=22-x
8x=3(22-x) => 8x=66-3x => 11x=66 => x=6
y=22-x => y=22-6=16

14b)

9x=4y       | * 3  => 27x=12y
2x+3y=40 | * 4  => 8x+12y=160; inlocuim cu 12y=27x si obtinem 
8x+27x=160 => 35x=160 => x=160/35 = 32/7 
y=27x/12=27*(32/7)/12=8/21

14c)

5x=3y | * 4 => 20x=12y
4y-3x=0,11 | *3 =>12y-9x=0,33 ; inlocuim pe 12y cu 20x => 20x-9x=0.33 => 11x=0,33 => x=0,33 / 11 = 3/100= 0.03
12y = 20*3/100 => y = 4/100 = 0.25