Question

Calculati urmatoarele exaecitii

Answer 1

$a). \displaystyle \frac{25}{100} \cdot y=17 \Rightarrow \frac{25y}{100} =17 \Rightarrow 25y=17 \cdot 100 \Rightarrow 25y=1700 \Leftrightarrow \\ \\ \Leftrightarrow y= \frac{1700}{25} \Rightarrow y=68 \\ \\ b). \frac{40}{100} \cdot z=25 \Rightarrow \frac{40z}{100} =25\Rightarrow 40z=25 \cdot 100 \Rightarrow 40z=2500 \Leftrightarrow \\ \\ \Leftrightarrow z = \frac{2500}{40} \Rightarrow z= \frac{125}{2}$

$\displaystyle c). \frac{60}{100} \cdot t=12 \Rightarrow \frac{60t}{100} =12 \Rightarrow 60t=12 \cdot 100 \Rightarrow 60t=1200 \Leftrightarrow \\ \\ \Leftrightarrow t= \frac{1200}{60} \Rightarrow t=20 \\ \\ d). \frac{80}{100} \cdot p=45\Rightarrow \frac{80p}{100} =45 \Rightarrow80p=45 \cdot 100 \Rightarrow 80p=4500 \Leftrightarrow \\ \\ \Leftrightarrow p= \frac{4500}{80} \Rightarrow p= \frac{225}{4}$