Toán Lớp 6: c)25-(x-5)=-415-(15-415) f)(x-3) (2x+6)=0

Question

Toán Lớp 6:  c)25-(x-5)=-415-(15-415) f)(x-3) (2x+6)=0

dongoctuan · Answer

~ Bạn tham khảo ~   c, 25-(x-5) = -415 - (15 - 415)   25-(x-5) = -415 - 15 + 415   25-(x-5 )= ( 415 - 415 ) - 15   25-(x-5)= 0 - 15   25-(x-5) = -15   x-5 = 25 - (-15)   x-5 = 40   x=40+5   x=45 Vậy  x = 45   f, (x-3)(2x+6)=0    ( left[  begin{array}{l}x-3=0  2x+6=0 end{array}  right. )     ( left[  begin{array}{l}x=3  2x=-6 end{array}  right. )    ( left[  begin{array}{l}x=3  x=-3 end{array}  right. )   Vậy  x &isin; { 3 ; -3 }   @Vịt v&agrave;ng

ngoclandiep · Answer

$c)25-(x-5)=-415-(15-415)$     $&rArr;25-(x-5)=-415-(-400)$     $&rArr;25-(x-5)=-15$     $&rArr;x-5=25-(-15)$     $&rArr;x-5=40$     $&rArr;x=40+5$     $&rArr;x=45$     $f)(x-3) (2x+6)=0$     $&rArr;$ ( left[  begin{array}{l}x-3=0  2x+6=0 end{array}  right. )      $&rArr;$ ( left[  begin{array}{l}x=3  2x=-6 end{array}  right. )      $&rArr;$ ( left[  begin{array}{l}x=3  x=-6:2 end{array}  right. )      $&rArr;$ ( left[  begin{array}{l}x=3  x=-3 end{array}  right. )