am test. va rog ajutati ma

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