4. To the store, $475 \mathrm{~kg}$ of fruit was delivered: apples, tangerines, and bananas. How many kg does each type of fruit weigh, if half of the apples weigh twice as much as $30 \%$ of the tangerines, and the bananas weigh $35 \mathrm{~kg}$ less than the apples?
4. Let unknown quantities be denoted as follows: for example, $j$ represents the quantity of apples in kg, $m$ represents the quantity of mandarins in kg, and $b$ represents the quantity of bananas in kg. We write the relationship between the quantities as $j+m+b=475$ and the equations $\frac{1}{2} j=2 \cdot \frac{30}{100} m$ and $b=j-35$. Solve the system of three equations with three unknowns. The solution is $j=180 \mathrm{~kg}, m=150 \mathrm{~kg}$, and $b=145 \mathrm{~kg}$.

| Writing the equation $j+m+b=475 \ldots \ldots \ldots \ldots \ldots \ldots \ldots \ldots$  Writing the equation $\frac{1}{2} j=2 \cdot \frac{30}{100} m$ or $5 j-6 m=0 \ldots \ldots \ldots \ldots$  Writing the equation $b=j-35$ or $j-b=35 \ldots \ldots \ldots \ldots \ldots$  Solving the system of three equations with three unknowns.  Solution $j=180$ kg. $m=150 \mathrm{~kg}$ and $b=145 \mathrm{~kg}$ |
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