с решением a) 5(x-4,3)=7(x-0,5) b) 3(x-15)+30=12x c)0,4x-(0,2x-3,2)=4,8

Question

Алгебра: с решением a) 5(x-4,3)=7(x-0,5) b) 3(x-15)+30=12x c)0,4x-(0,2x-3,2)=4,8

diankasht · Accepted Answer

sin105°*cos75°  = sin(180° -75°)*cos75° = sin75°*cos75°  =(sin2*75°)/2 = (sin150°)/2 =(sin(180°- 30°))/2 = (sin30°)/2 =(1/2) /2 =1/4. 1)  sin105°*sin75°  = sin(180° -75°)*sin75° = sin75°*sin75° =sin²75°= (1 -cos2*75°)/2 =(1 -cos150°)/2  = (1 -cos(180° -30°) )/2  = (1+cos30°) /2 = (2+√3) / 4 . * * * sin²75° =(sin45°cos30° + cos45°sin30°) ² = ( (1/√2)*(√3)/2 +(1/√2)*(1)/2)  ) ²  =(1/8) *(√3 +1) ² =(1/8) *(3 +2√3 +1)= (1/4)  *(2 +√3 )= (2 +√3 ) /4. --- 2) 4sin(π/6 -β)cos(π/6+β)=  4 *(sin(π/6 -β+π/6+β) + sin(π/6...

MOGZ ответил

с решением a) 5(x-4,3)=7(x-0,5)

b) 3(x-15)+30=12x

c)0,4x-(0,2x-3,2)=4,8