there is a error for solving equations

>> d = 'x^2 + 9*x –7 = 0'; >> solve(d) Error using solve>processString (line 354) ' x^2 + 9*x –7 = 0 ' is not a valid expression or equation.

Error in solve>getEqns (line 284) eqns = processString(eqns, v, vc);

Error in solve (line 160) [eqns,vars,options] = getEqns(varargin{:});

Answer 1

[A Jenkins]

When I copy/paste your code, I get that the '–' is the wrong character: it is the 'dash' (U+2013) character instead of the 'minus' (U+002D) character.

Does this work?

d = 'x^2 + 9*x - 7 = 0';
solve(d)

Answer 2

[math search]

Thank you it works now but how can you find names of that characters?

[A Jenkins]

Use Data Type Conversion.

The following worked for me, though it might be system dependent.

>> dec2hex('-')

ans =

2D

>> dec2hex('–')

ans =

2013

List of Unicode Characters