Răspuns :
Explicație pas cu pas:
x = 5/10 : -(-7/4) = - 5/10 * 4/7= - 20/70 = - 2/7
a = 4/15 + (23-2)/90 = 4/15 + 21/90 = 24/90+21/90=45/90 =1/2
[tex]\it e)\ \ -\dfrac{7}{4}x=0,5|_{\cdot4} \Rightarrow -7x=2|_{\cdot(-1)} \Rightarrow 7x=-2 \Rightarrow x=\dfrac{-2}{7}=-\dfrac{2}{7}\\ \\ \\ f)\ \ a-0,2(3)=\dfrac{^{6)}4}{\ 15} \Rightarrow a-\dfrac{23-2}{90}= \dfrac{24}{90} \Rightarrow a=\dfrac{24}{90}+\dfrac{21}{90}=\dfrac{45}{90}=\dfrac{1}{2}[/tex]