E URGENT VA ROG REPEDE DAU COROANA!!!
Răspunsuri la întrebare
Răspuns:
Explicație pas cu pas:
3x/7 + 2x/14 = 6/7
3x/7 + x/7 = 6/7
4x/7 = 6/7
x = 6/7 : 4/7 = 6/7*7/4 = 6/4 = 3/2
____________
-y/2 + 5y/4 = -1/2
-2y/4 + 5y/4 = -1/2
3y/4 = -1/2
y = -1/2 : 3/4 = -1/2 * 4/3 = -2/3
____________
ma = (15/4 + 5/2 + 7/2) : 3 = (15/4 + 12/2) : 3 = (15/4 + 24/4) : 3
= 39/4 : 3 = 39/4*1/3 = 13/4
____________
x/y = 10/5
x/10 = y/5 = k
x = 10k
y = 5k
a)
x + x/5 = 10k + 10k/5 = 10k + 2k = 12k
y + x = 5k + 10k = 15k
12k/15k = 12/15 = 4/5
b)
5x = 5*10k = 50k
2x + y = 2*10k + 5k = 20k + 5k = 25k
50k/25k + 5k/10k = 2 + 1/2 = 4/2 + 1/2 = 5/2
____________
100*22/100 = 22
1000*9,5/100 = 95
Explicație pas cu pas:
1) a. x*3/7 + 2x/14 = 3x/7 + x/7 = 4x/7
4x/7 = 6/7
4x = 6 → x = 6/4 = 3/2
b. -y/2 + 5y/4 = -1/2
-2y/4 + 5y/4 = -2/4
3y/4 = -2/4
y=-2/3
2) ma = (15/4 + 5/2 + 7/2)/3 =
=(15/4 + 10/4 +14/4)/3=
=39/4*3 = 13/4
3) Produsul mezilor e egal cu cel al extremelor:
5*x = 10*y
x = 2y
3) a. (2y+2y/5)/(2y+y) =
= (10y/5 + 2y/5)/3y=
=12y/5*3y=
=4/5
b. 10y/(4y+y) + y/2y =
=10y/5y + y/2y=
=1/2 + 1/2=
=2*1/2
= 1
4)
a. 22% din 100 = 22/100 * 100 = 22
b. 9,5% din 1000 = 9,5/100 *1000 = 9,5 * 10 = 95
Sper că te-am ajutat! :)