Tính định thức cấp 4 5. Giúp mình vs ạ. File bài ở dưới

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

Solve the equation - 2(m -30) = -6m a-15 b-13 c-8 d8

Two friends are reading books. jimmy reads a book with 21,356 words. his friend bob reads a book with one-and-a-half times as many words. which expression represents the number of words bob reads?