If you simplify the equation, it goes to 4x+5=3x+6. Subtract 5 from both sides and you get 4x= 3x+1. The only number that satisfies that equation is 1.
Because you need a number between 1 and 10 for scientific notation. So you move the decimal over 11 places. Since you move it to the right, it becomes a negative exponent.
