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1. a) calculate: (7 supra 4+1 supra 60* 12 supra23

b) (5 supra 6 - 1 supra 3): la 1 supra 4.

c)media ponderata a numerelor a=2,7 si b=4,8 (6) cu ponderile 4 si 6.

2. Rezolvati in Q+,ecuatiile.

a) 3,5x +3,35= 20,85.

b)0,8 (x+ 0,2 )=4,96. Ajutooorrrr,va rog frumooos!!!!! Tema de clasa a6-a



Răspuns :

1) a) [tex] \frac{7}{4}+ \frac{1}{60}* \frac{12}{23}= \frac{7}{4}+ \frac{1}{5}* \frac{1}{23} = \frac{7}{4}+ \frac{1}{115}= \frac{805}{460}+ \frac{4}{460}= \frac{809}{460} [/tex]
b) [tex] (\frac{5}{6}- \frac{1}{3}): \frac{1}{4}=( \frac{5}{6}- \frac{2}{6})*4= \frac{3}{6}*4 = \frac{12}{6}=2 [/tex]

2)a) 3,5x+3,35=20,85
3,5x=20,85-3,35
3,5x=17,5
x=17,5:3,35
x=5

b)0,8(x+0,2)=4,96
0,8x+0,16=4,96
0,8x=4,96-0,16
0,8x=4,80
x=4,80:0,8
x=6