Question

17,18,19,20,21,22!!!

Answer 1

17)8,6x+2x=10+43
10,6x=53
x=10,6:53
x=2
18)5,6x+1,2x-34=5x+20
5,6x+1,2x-5x=20+34
1,8x=54
x=54:1,8
x=30
19)A=3/8×b=3b/8
a+b=11/5
3b/8+b=11/5
numitor 8×5=40
3b×5+40b=11×8
15b+40b=88
55b=88. împărțim cu 11
5b=8;b=8/5
a=3×8/5×8=3/5
20)B=3a/5
a-b=17,2
a-3a/5=17,2. numitor 5
5a-3a=5×17,2
2a=86
a=86:2=43. ;b=3×43/
5=129/5
21)A+b=4,29
a-2b=1,14
a=1,14+2b
1,14+2b+b=4,29
3b=4,29-1,14
3b=3,15
b=3,15:3
b=1,05
a=1,14+2b
a=1,14+2×1,05
a=1,14+2,10
a=3,24