Odpowiedź i szczegółowe wyjaśnienie:
[tex]\dfrac{100-p}{100}\cdot\dfrac{160}{100}=\dfrac{100-(p-30)}{100}\\\\\dfrac{160(100-p)}{100\cdot100}=\dfrac{100-(p-30)}{100}\\\\160(100-p)\cdot100 = 100\cdot100\cdot(100-(p-30))\ /:100\\\\160(100-p)=100(100-p+30)\\\\160(100-p)=100(130-p)\ /:10\\\\16(100-p)=10(130-p)[/tex]