mathcad adding two equations with one variable

[HB_10330845]

I checked this section for a similar question and could not locate one. It's simple one I'm guessing but I just cant figure it out.

Two equations: 3x^2 + 4x -7 and 5x^2-7x+3

(or whatever one variable equation).

How can I add them in mathcad so I get the answer 8x^2 -3x-4 ?

Thanks. Mr Noob....

[ttokoro · Accepted solution]

[HB_10330845]

Thanks for your Explanation.

[Werner_E]

What you show are not equations.

If your goal is just to do calculation using unknown variables not assigned a value, you have to use symbolic evaluation as ttokoro had shown.

You get the symbolic "equal sign" (the right arrow) either via the keyboard short (Ctrl and .) or via the menu: Math-Operators-Definition and Evaluation.

[LucMeekes]

"What you show are not equations."

But both Mathcad and Prime are happy to treat such expressions as equations, assuming that their evaluation result equals 0:

Success!
Luc

[Werner_E]

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assuming that their evaluation result equals 0:

An assumption which is mathematically doubtful, but often convenient when working with Mathcad.

Adding two equations would mean to me to add

2x +3y  =8z

and

5x-4y=-3z

and get as a result

7x-y=5z

Thats something neither Mathcad nor Prime can do in a natural way.

It also would be beneficial to be able to do operations like "add 4y" to both sides of an equation or to be able to have access to the LHS or RHS of an equation, but unfortunately the symbolics is not capable enough to provide the necessary operators, functions and modifiers.

[LucMeekes]

Challenge accepted:

or:

Will (most probably) not work beyond Mathcad 11, let alone Prime.

Success!
Luc

[Werner_E]

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@LucMeekes wrote:

Challenge accepted:

🙂

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Will (most probably) not work beyond Mathcad 11, let alone Prime.

Correct!  "op" is unknown