Question

rpd dau coroana la cine ma ajuta​

Answer 1

Răspuns:

notam cu x= kg mandarine intr-o cutie

               y= kg portocale intr-o cutie , x,y=?

$\left \{ {{4x+6y=180} \atop {3x+4y=125}} \right. \\\\\\\\\left \{ {{2x+3y=90 (am . simplificat. cu. 2)} \atop {3x+4y=125}} \right\\. x=( 90-3y):2 \\3(90-3y):2+4y=125\\270-9y+8y=250\\ (am . inmultit . cu. 2. ca . sa. scap. de. numitor)270-y=250\\\\y=270-250\\y=20\\x=(90-60):2=15\\X=15 \\ Y=20\\\\verificare: 3*15+4*20=45+80=125$