Mathematics

Question

x + y = 10, x - y = 0 Please solve and explain.

1 Answer

  • We'll use elimination for this system of equations. What variable should get canceled? The x or y? Well to cancel, we need a positive and negative variable.

    x + y = 10
    x - y = 0

    In this case, the y's will cancel out.
    Then we will add the x's together and the 10 and 0.

    x + y = 10
    x - y = 0

    Becomes

    2x = 10

    Now, solve for x. Just simply divide by 2.

    2x / 2 = 10 / 2

    x = 5

    Now we know what the x variable is equal to!

    To solve for the y variable, just replace the x variable in one of the equation and solve for y.

    I'll use the x + y = 10 equation

    We know x is equal to 5.

    5 + y = 10

    Subtract both sides by 5.

    5 - 5 + y = 10 - 5

    y = 5

    So, both x and y are equal to 5.




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