Question

решите уравнение 1) (x -5)^2 +4x = 25 2)(x6)(x7) = -x + 7 3) 6x(0.5 + 3x) - 15x^2 = 0 4) (4 - x)(4 + x) = x^2 - 2

Answer 1

1) (х-5)²+4х=25                       3)6х(0,5+3х)-15х²=0
    х²-10х+25+4х-25=0                3х+18х²-15х²=0
    х²-6х=0                                     3х+3х²=0
   х(х-6)=0                                      3х(1+х)=0
  х₁=0    х-6=0                                  3х=0         1+х=0
             х₂=6                                       х=0           х=-1


4)     (4-х)(4+х)=х²-2
        16-4х+4х-х²-х²+2=0
            -2х²+18=0
             -2х²=-18
                х²=9
                х=3