Zadanie 14
a)
z = 4a - 7
4a-7=z |+7
4a = z+7 |:4
a=\frac{z+7}{4}
b)
t = \frac{1-a}{3} |*3
3t=1-a |-1
a=1-3t
c)
f = \frac{ab}{b+1}
ab=f(b+1)
a=\frac{f(b+1)}{b}
d)
y = \frac{3(a-2)}{1-b}
3(a-2)=y(1-b)
3a-2=y(1-b)
3a=y(1-b)+2
a=\frac{y(1-b)+2}{3}
Zadanie 15
V = \frac{2(a+b)}{a}-1
\frac{2(a+b)}{a}-1=V
\frac{2a}{a}+\frac{2b}{a}-1=V
2+\frac{2b}{a}-1=V
1+{2b}{a}=V
\frac{2b}{a}=V-1
a(V-1)=2b
a=\frac{2b}{V-1}