vreau sa imi rezolvati toate exercitile din aceasta poza sau macar jumate.
dau coroana+inima+5 stele celui care imi rezolva toate exercitile cu tot cu rezolvare.
Răspunsuri la întrebare
Răspuns:
1.a)
216×753-753×196+20×247=
753×(216-196)+4.940=
753×20+4.940= 15.060+4.940= 20.000
b)
3,07×20+2,5×0,16=61,4+0,4= 61,8
c)
4,32:0,4-0,1²×80=
10,8- 0,01×80= 10,8-0,8= 10
d)
[(108÷3²×2-2²)×3³-4²]÷40=
[(108÷9×2-4)×27-16]÷40=
[(12×2-4)×27-16]÷40=
(20×27-16)÷40= 524÷40= 13,1
2.a)
1/3 □ 0,3 => 1/3 □ 3/10 => 10/30 > 9/30
1/3 > 0,3
b)
2,7(28) □ 2,72(8) => 2,7282828 < 2,7288888
c)
13/14 □ 15/16 => 104/112 < 105/112
13/14 < 15/16
3.a)
A={170, 172, 174, 176, 178}
B={5, 4, 3, 2, 1}
A n B= Ø
AUB= {1,2,3,4,5,170,172,174,176,178}
B/A={1,2,3,4,5}
4.
P= 10,4dm. = 104cm.
L=?
l= 5/8×L
P= L×2+l×2
104cm= 2L+(5/8×L)×2
104cm= 2L+5L/8×2
104cm= 2L/1+10L/8
104cm= 16L/8+10L/8
104/1= 26L/8
26L×1=8×104
26L= 832
L= 832÷26= 32cm.
L=32cm. = 3,2dm.
l= 5/8×32=20cm. =2dm.
A= L×l
A= 3,2×2= 6,4dm² sau 640cm²