Question

ajutor cu ex 21 și22, sau cu unu dintre ele!

Answer 1

/=fractie
21.
a/b=13/4=> a=13k
b=4k
a)a-b=27
13k-4k=27
9k=27/:9
k=3 => a=13x3=39
b=4x3=12
b)a+b=34
13k+4k=34
17k=34/:34
k=2=>a=13x2=26
b=4x2=8
c)5a+2b=365
5x13k+2x4k=365
65k+8k=365
73k=365/:73
k=5=>a=13x5=65
b=4x5=20
22.a/11=b/8=> a=11k
b=8k
a)a+b=76
11k+8k=76
19k=76/:19
k=4=>a=11x4=44
b=8x4=32
b)a-b=0,9
11k-8k=o,9
3k=0,9/:3
k=0,3=> a= 11x 0,3=3,3
b=8x0,3=2,4
c)3a+b=31
3x11k+8k=31
41k=31/:41
k=0,75=>a=11x0,75=8,25
b=8x0,75=6