To find the resistance of the unknown component \( x \), we first use Ohm's law, \( V = IR \). The total resistance \( R \) of the circuit is given as \( 5x + 20 \) ohms. Substituting the values into Ohm's law, we have \( 90 = 2.25(5x + 20) \). Solving for \( x \):
-
Divide both sides by 2.25: \[ 40 = 5x + 20 \]
-
Subtract 20 from both sides: \[ 20 = 5x \]
-
Divide by 5: \[ x = 4 \]
Thus, the resistance of the unknown component is \( 4 , \Omega \).