Question

Решите. 7 класс, срочно. Алгебра

Answer 1

(7m+8)(8-7m)=64-49m^2
a^2-100=(a-10)(a+!0)
c^2 -400 b^2=(c- 20b)(c+20b)
25x^2-1=0
(5x-1)(5x+1)=0
5x-1=0
5x=1
x1=1/5
5x+1=0
5x= - 1
x2= - 1/5
(2x-1)^2-81=0
2x-1=+-9
2x-1=9
2x=10
x1=5
2x-1= -9
2x= -9 +1
2x= -8
x2= - 4
29^2-28^2=(29-28)(29+28)=1*57=57