The total toll charge for one car and five bicycles to cross a bridge is $7.50. The toll for a car is $1.50 more than for a bicycle. Find the cost for a car to cross the bridge.

You read the question wrong

cost for bike --- x

cost for car --- x + 1.5

x + 5(x+1.5) = 7.5
x + 5x + 7.5 = 7.5
6x = 0
x = 0

A bike costs nothing and a car costs $1.50

by common sense:
Since the extra charge for the 5 cars would have been 5(1.5) or 7.50, but 7.50 was the total, the bikes must have been free.

To find the cost for a car to cross the bridge, let's first define some variables:

Let's call the cost for a bicycle to cross the bridge "x".
Therefore, the cost for a car to cross the bridge would be "x + $1.50" (since it is $1.50 more than the cost for a bicycle).

Now, let's set up an equation based on the given information:
The total toll charge for one car and five bicycles is $7.50.

So, the equation would be:
1 car + 5 bicycles = $7.50

Using the variables we defined earlier, we can write the equation as:
(x + $1.50) + 5x = $7.50

Now, we can solve the equation to find the value of x (the cost for a bicycle).

(x + $1.50) + 5x = $7.50
6x + $1.50 = $7.50
6x = $7.50 - $1.50
6x = $6.00

Dividing both sides by 6:
x = $6.00 / 6
x = $1.00

So, the cost for a bicycle to cross the bridge is $1.00.

Since the cost for a car is $1.50 more than for a bicycle,
the cost for a car to cross the bridge would be:
$1.00 + $1.50 = $2.50

Therefore, the cost for a car to cross the bridge is $2.50.