am test. va rog ajutati ma
Răspunsuri la întrebare
1. a. 30/100 × 10=3
b. x/100 × 15=3
x/100=3/15
x=3/15×100
x=20
c.5/100 × 20=1
20-1=19 exercitii ramase
2. 2x+1= 48/27 × 16
2x+1=16/9 × 16
2x+1= 256/9
2x=256/9 - 1
2x= 256/9 - 9/9
2x=247/9
x=247/9/2
x=247/18
3. 12/288=x/720
=30 de muncitori
4. 6/8=x/9
=termina in 6 ore si 45 de minute
5. a b c dp 3 4 5
a/3=b/4=c/5=k
4a+3b+60c=1296
4•3k+3•4k+60•5k=1296
324k=1296
k=4
a=4•4=16
b=3•4=12
c=5•4=20
Explicație pas cu pas:
1.
a)30 supra 100×10=3
b)x supra 100×15=3
x=20
c)5 supra 100 ×20=1ex rezolvat si mai are de rezolvat 19
2.
2x+1×48=16×27
2x+48=432
2x=384
x=384:2
x=192
3.
12 supra288=x supra720
x=720×12 supra 288
x=30 de muncitori executa 720 de piese
4.
6 supra 8=9 supra x
x=8×9 supra 6
x=12
5.
a supra 3=b supra 4=c supra 5
a=3k
b=4k
c=5k
4a+3b+60c=1296
4×3k+3×4k+60×5k=1296
12k+12k+300k=1296
324k=1296
k=1296:324
k=4
a=3×4=12
b=4×4=16
c=5×4=20