finished math thing

function removedec(number)
    kek = number
    local strnum = tostring(number)
    for i=1,#strnum do
        if string.sub(strnum,i,i) == "." and string.sub(strnum,i+1,i+1) == "0" and string.sub(strnum,i+2,i+2) == ""  then
            kek = tonumber(string.sub(strnum,1,i-1))
        end
    end
    return kek
end

function calc(strin)
    if strin:sub(1,7):lower() == "x^2+y^2" then
        if strin:sub(8,8):lower() == "+" then
            neg1 = false
        else
            neg1 = true
        end
        for i=9,100 do
            if strin:sub(i,i):lower() == "x" then
                numx = string.sub(strin,9,i-1)
                currenti = i+1
                break
            end
        end
        if strin:sub(currenti,currenti):lower() == "+" then
            neg2 = false
        else
            neg2 = true
        end
        for i=currenti,200 do
            if strin:sub(i,i):lower() == "y" then
                numy = string.sub(strin,currenti+1,i-1)
                currenti = i+1
                break
            end
        end
         if strin:sub(currenti,currenti):lower() == "+" then
            neg3 = false
        else
            neg3 = true
        end
        for i=currenti,300 do
            if strin:sub(i,i):lower() == "=" then
                currenti2 = i
                numout = string.sub(strin,currenti+1,i-1)
                if string.sub(strin,currenti,currenti) == "+" then
                    neg4 = false
                else
                    neg4 = true
                end
                break
            end
        end
        ----
        nexnumber = string.sub(strin,currenti2)
        ----
        numx2 = removedec((tonumber(numx)/2)*(tonumber(numx)/2))
        numy2 = removedec((tonumber(numy)/2)*(tonumber(numy)/2))
        ----
        if neg1 == false then
            rea1 =  "x² + "..numx.."x"
            rea2 = "x² + "..numx.."x"
            rea3 = "x² + "..numx.."x"
            rea4 = "x² + "..numx.."x + "..numx2
            rea5 = "(x + "..removedec((numx/2))..")²"
        else
            rea1 = "x² - "..numx.."x"
            rea2 = "x² - "..numx.."x"
            rea3 = "x² - "..numx.."x"
            rea4 = "x² - "..numx.."x + "..numx2
            rea5 = "(x - "..removedec(((numx/2)*1))..")²"
        end
        ----
        if neg2 == false then
            bea1 = "y² + "..numy.."y"
            bea2 = "y² + "..numy.."y"
            bea3 = "y² + "..numy.."y"
            bea4 = "y² + "..numy.."y + "..numy2
            bea5 = "(y + "..removedec((numy/2))..")²"
        else
            bea1 = "y² - "..numy.."y"
            bea2 = "y² - "..numy.."y"
            bea3 = "y² - "..numy.."y"
            bea4 = "y² - "..numy.."y + "..numy2
            bea5 = "(y - "..removedec(((numy/2)*1))..")²"
        end
        ----w
        if neg4 == false then
            rewrite = rea1.." + "..bea1.." + "..numout.." = 0"
            numout = tonumber(numout)
        else
            rewrite = rea1.." + "..bea1.." - "..numout.." = 0"
            numout = tonumber(numout)*-1
        end
        print(rewrite)
        rewrite2 = rea2.." + "..bea2.." = "..numout*-1
        print(rewrite2)
        rewrite3 = rea3.." + ___ + "..bea3.." + ___  = "..(numout*-1).." + ___ + ___"
        print(rewrite3)
        rewrite4 = rea4.." + "..bea4.."  = "..(numout*-1).." + "..numx2.." + "..numy2
        print(rewrite4)
        rewrite5 = rea5.." + "..bea5.." = "..((numout*-1)+numx2+numy2)
        print(rewrite5)

    end
end
calc("x^2+y^2+4x-4y+0=0")