If a car increases its speed by 20% from place a to place B, it will arrive ahead of time. If it runs at the original speed of 100 km and then increases its speed by 30%, it will be just right How many kilometers is the distance between a and B? Set an unknown number to write out the process of solving the equation

If a car increases its speed by 20% from place a to place B, it will arrive ahead of time. If it runs at the original speed of 100 km and then increases its speed by 30%, it will be just right How many kilometers is the distance between a and B? Set an unknown number to write out the process of solving the equation

Assuming that the original speed is x and the distance between the two places is y km, the time to increase the speed by 20% is Y / 1.2x, and the time to increase the speed by 30% is 100 / x + (y-100) / 1.3x2, which is the same as Y / 1.2x = 100 / x + (y-100) / 1.3x = 130 / 1.3x + (y-100) / 1.3x = (y + 30) / 1.3x. The equation is transformed into 1.3xy = 1.2