A

1103049404

Level: 
A
In addition to solving equation \( ax+b=cx+d \) algebraically, you can also solve it graphically. When the lines \( y=ax+b \) and \( y=cx+d \) are graphed, you look for the intersection of these lines. In the pictures below are graphed lines \( y=ax+b \) and \( y=cx+d\). Choose the picture in which the equation \( ax+b=cx+d \) has only one non-negative solution.

1103085403

Level: 
A
Two resistors of unknown resistances \( R_1 \) and \( R_2 \), where \( R_1 < R_2 \) are connected in series (Figure A) and total resistance of the circuit is \( R_S=64\,\Omega \). If the resistors are connected in parallel (Figure B), the total resistance \( R_P=15\,\Omega \). Find \( R_1 \).
\( 24 \)
\( 22 \)
\( 12 \)
\( 15 \)