eqauttons solveing non linear why i am geting this error

[x,y] = solve([x + y == 1000 (0.4818*10.^-7)*x.^4 - (0.9089*10.^-4)*x.^3 + (0.6842*10.^-1)*x.^2 - (0.2106*10.^2)*x +9860 == (0.9592*10.^-7)*y.^4 - (0.7811*10.^-4)*y.^3 + (0.2625*10.^-1)*y.^2 - (0.2189*10)*y +9003],[x,y])

Error using sym/solve>getEqns

Input argument contains an empty equation or variable.

Error in sym/solve (line 226)

[eqns,vars,options] = getEqns(varargin{:});

Related documentation

Answer 1

[Walter Roberson]

syms x y
eqn = [x + y == 1000,0.4818*10^-7*x^4 - 0.9089*10^-4 + 0.6842*10^-1*x^2 - 0.2106*10^2*x + 9860 == 0.9592*10^-7*y^4 - 0.7811*10^-4*y^3 + 0.2625*10^-1*y^2 - 0.2189*10*y + 9003]

eqn = 

sol = solve(eqn, [x y], 'MaxDegree', 4)

sol = struct with fields:
    x: [4×1 sym]
    y: [4×1 sym]

sol.x

ans = 

sol.y

ans = 

vpa(sol.x)

ans = 

vpa(sol.y)

ans = 

[Walter Roberson]

As to what the problem was: notice

0.2106*10^2*x +9860
0.2189*10*y +9003

inside of [], those +9860 and +9003 are not additions: they are "unary plus". Just like you can have

[-1 -1 +1 -1 +1 +1]

and expect to get out a vector of length 6, when you have whitespace then plus or minus, then immediately a number, that is unary plus or unary minus rather than addition or subtraction. For addition or subtraction you either need to have no space before the + or -, or else you need to have a space after the plus or minus

3-5   -> subtraction
3 - 5  -> subtraction
3 -5  -> unary minus

[Bader Herzallah]

[Bader Herzallah]

this is the quation

first eqaution is lp+lq=1000

the sconde one is IRp=IRq

the answers should be

Lp=732.5

Lq=267.5

how i can get this answer in matlab