Question

Va rog pun 39 de puncte!!!este poza

Answer 1

Sper ca te-am ajutat! :))

Answer 2

1.
a)x+12,5=123,75⇔
⇔x=123,75-12,5⇔
⇔c=111,25.
 
b)x-2,05=3,147⇔
⇔x=3,147+2,05⇔
⇔x=5,197

2.
x:3,2=5⇔
⇔x=5×3,2⇔
⇔x=16

3.
a)24 și 500
ma=(24+500):2⇔
⇔ma=524:2⇔
⇔ma=261

b)14,5 și 21,5
ma=(14,5+21,5):2⇔
⇔ma=36:2⇔
⇔ma=28

4./=fracție
3/5 din 800l=
=3/5×800l=
=3×160l=
=480l

5.(o alegi pe care vrei)
0,6×0,2=0,12
0,3×0,4=0,12
0,1×0,12=0,12

6.
a)25/100 din 800lei=
=25/100×800=
=25×8=
=200lei

b)30/100 din 510kg=
=30/100×510=
=0,30×510=
=153

7.
a)3,16:x=10³⇔
⇔3,16:x=1000⇔
⇔x=3,16:1000⇔
⇔x=0,003,16

b)x:1,24=10³⇔
⇔x:1,24=1000⇔
⇔x=1,24:1000⇔
⇔x=0,00124

8.
a+b=25,8
a=1/5×b

a+b=25,8⇔
⇔1/5×b+b=25,8⇔
⇔b/5+b=25,8⇔
⇔b/5+5b/5=25,8⇔
⇔6b/5=25.8⇔
⇔6b:5=25,8⇔
⇔6b=25,8×5⇔
⇔6b=129⇔
⇔b=129:6⇔
⇔b=21,5 ⇒ b=215/10

a=1/5×21,5⇔
⇔a=4,3 ⇒ a=43/10

9.
ma=(x+20,23):2⇔
⇔30,54=(x+20,23):2⇔
⇔(x+20,23):2=30,54⇔
⇔x+20,23=30,54×2⇔
⇔x+20,23=61,08⇔
⇔x=61,08-20,23⇔
⇔x=40,85 ⇒ x=4085/100

10.
a)0,2x-1,25=7,5⇔
⇔0,2x=7,5+1,25⇔
⇔0,2x=8,75⇔
⇔x=8,75:0,2⇔
⇔x=43,75

b)1,2x+3,6=9,6⇔
⇔1,2x=9,6-3,6⇔
⇔1,2x=6⇔
⇔x=6:1,2⇔
⇔x=5