双未知数近似求解

a = -20
b = -20
end = False
nec = 0
while a < 10:
    a = round(a+0.001, 4)
    b =1
    while b < 10:
        b = round(b+0.001, 4)
        cc = a+2*a*b+b
        if cc == 8 or 0<8-cc<0.00001:
            print(f"近似结果a：{round(a, 2)},b:{round(b, 2)}")
            print(round(cc, 2))
            print(round(a+b, 2))
            end = True
            break
    nec = nec+1
    if nec>1000:
        print(111)
        nec = 0
    if end:
        break

a = -20
b = -20
end = False
nec = 0
while a < 10:
    a = round(a+0.001, 4)
    b =1
    while b < 10:
        b = round(b+0.001, 4)
        cc = a+2*a*b+b
        if cc == 8 :
            print(f"结果a：{round(a, 2)},b:{round(b, 2)}")
            print(round(cc, 2))
            print(round(a+b, 2))
            end = True
            break
    nec = nec+1
    if nec>1000:
        print(111)
        nec = 0
    if end:
        break