Please help I need this​

Which of these equations, when solved, gives a different value of x than the other three? a9.1 = -0.2x + 10 b10 = 9.1 + 0.2x c10 – 0.2x = 9.1 d9.1 – 10 = 0.2x

Write the equations in logarithmic form 7^3=343

Def rotates 90 clockwise about point a to create d’ e’ f’. therefore, which equation must be true ?