The Easiest Way to Understand Algebra. Algebra equations with answers and solutions. Sergey D. Skudaev

Чтение книги онлайн.

      Solve for X.

      1. 5aX – 5bX = 10b – 10a

      2. aX – bX – cX = c + b – a

      3. 2X – 3aX = 6a – 4

      4. 3aX – 9bX = 27b – 9a

      5. 4bX – cX = 8c – 32b

      6. abX – acX = ac – ab

      7. X/2 – aX = 1 – 2a

      8. aX/5 +2a = 5a – 4aX

      You can find answers in appendix 1 and solutions in appendix 2.

      2. SYSTEM OF EQUATIONS

      Look at the equation X + Y = 3. X and Y are unknown. You cańt find neither X nor Y from this equation. You need additional information about the “relationship” between them. Such information may be included in an additional equation. For example: X – Y = – 1. Now you have a system of 2 equations:

      1. X + Y = 3

      X – Y = -1

      There are several ways to solve it. The first way: solve for X in any equation, for example, the first one.

      In order to do that, subtract Y from each side of the equation:

      X + Y – Y = 3 – Y; Find X

      X = 3 – Y

      Then put (3 – Y) in place of X in the second equation (X – Y = -1).

      You will obtain: 3 – Y – Y = -1 or 3 – 2Y = -1

      Now solve that equation for Y. Add 2Y to the both sides of the equation.

      3 – 2Y +2Y = -1 +2Y

      3 = -1 +2Y

      Add 1 to the both sides of the equation.

      3 +1 = -1 +1 +2Y

      4 = 2Y