Toán Lớp 9: 4x^2-9x=0 x^2-7x+6=0 3x^2+5x-8=0

Question

Toán Lớp 9:  4x^2-9x=0 x^2-7x+6=0 3x^2+5x-8=0

thienthanh · Answer

Milk gửi ạ

trucoanh55 · Answer

4x^2-9x=0   &hArr; x(4x&minus;9)=0       ( left[  begin{array}{l}x=0  x= dfrac{9}{4} end{array}  right. )          x^2 - 7x+6=0         &hArr;  ( left[  begin{array}{l}a+b=&minus;7  ab=6 end{array}  right. )          &hArr;  ( left[  begin{array}{l}&minus;1,&minus;6  -2,-3 end{array}  right. )          &hArr;  ( left[  begin{array}{l}&minus;1&minus;6=&minus;7  &minus;2&minus;3=&minus;5 end{array}  right. )          &hArr;  ( left[  begin{array}{l}a=-6  b=&minus;1 end{array}  right. )       &hArr; (x&minus;6)(x&minus;1)         ( left[  begin{array}{l}x=6  x=1 end{array}  right. )              3x^2+5x-8=0             &hArr;  ( left[  begin{array}{l}a+b=5  ab=3(&minus;8)=&minus;24 end{array}  right. )              &hArr;  ( left[  begin{array}{l}&minus;1,24  &minus;2,12  &minus;3,8  &minus;4,6 end{array}  right. )              &hArr;  ( left[  begin{array}{l}&minus;1+24=23  &minus;2+12=10  &minus;3+8=5  &minus;4+6=2 end{array}  right. )              &hArr;  ( left[  begin{array}{l}a=&minus;3  b=8 end{array}  right. )         &hArr; (3x^2&minus;3x)+(8x&minus;8)   &hArr; 3x(x&minus;1)+8(x&minus;1)   &hArr; (x&minus;1)(3x+8)         ( left[  begin{array}{l}x=1  x=- dfrac{8}{3}  end{array}  right. )               Cho m&igrave;nh xin hay nhất nha bạn               @Drew Mclntyre