標題:
發問:
Solve the simultaneous equations: . x+y=5 { . x-y=3 __________ . 7x+2y=11 { . 7x-y=5 __________ . x+2y=3 { . 4x-5y=6 __________ . 2(x+y)-x=0 { . 2(x+y)-y=3 __________
最佳解答:
x+y=5 { . x-y=3 x = 5-y -----(1) x = 3+y ------(2) 把(1)代入(2) 5- y = 3+y 2 = 2y y = 1 把ｙ= 1 入（１） x = 5-1 x = 4 ------------------------------- 7x+2y=11 { . 7x-y=5 7x = 11-2y x = 11-2y / 7 ---------(1) 7x = 5+y x = 5+y / 7 --------(2) 把(1) 代入 (2) 11-2y/ 7 = 5+y /7 11-2y = 5+y 6 = 3y y=2 把y=2入 (2) x =5+ 2 /7 x = 1 --------------------------- x+2y=3 { . 4x-5y=6 __________ x = 3-2y --------(1) 4x =6+5y x = 6+5y /4 -----------(2) 把(1)入(2) 3-2y = 6+5y/4 4(3-2y) = 6+5y 12-8y = 6+5y 6 = 13y y = 6/13 把y=6/13 入 (1) x+ 2(6/13) =3 x = 3- 12/13 x = 27/13 ------------------------ 2(x+y)-x=0 { . 2(x+y)-y=3 2x + 2y -x =0 x+2y=0 x= -2y -------(1) 2x+2y-y=3 2x+y=3 x= 3-y/2 ------(2) 把(1)入(2) -2y=3-y/2 -4y=3-y -3y =3 y= -1 把y= -1 入(1) x= -2( -1) x=2
其他解答:
此文章來自奇摩知識+如有不便請留言告知
F.2 Maths發問:
Solve the simultaneous equations: . x+y=5 { . x-y=3 __________ . 7x+2y=11 { . 7x-y=5 __________ . x+2y=3 { . 4x-5y=6 __________ . 2(x+y)-x=0 { . 2(x+y)-y=3 __________
最佳解答:
x+y=5 { . x-y=3 x = 5-y -----(1) x = 3+y ------(2) 把(1)代入(2) 5- y = 3+y 2 = 2y y = 1 把ｙ= 1 入（１） x = 5-1 x = 4 ------------------------------- 7x+2y=11 { . 7x-y=5 7x = 11-2y x = 11-2y / 7 ---------(1) 7x = 5+y x = 5+y / 7 --------(2) 把(1) 代入 (2) 11-2y/ 7 = 5+y /7 11-2y = 5+y 6 = 3y y=2 把y=2入 (2) x =5+ 2 /7 x = 1 --------------------------- x+2y=3 { . 4x-5y=6 __________ x = 3-2y --------(1) 4x =6+5y x = 6+5y /4 -----------(2) 把(1)入(2) 3-2y = 6+5y/4 4(3-2y) = 6+5y 12-8y = 6+5y 6 = 13y y = 6/13 把y=6/13 入 (1) x+ 2(6/13) =3 x = 3- 12/13 x = 27/13 ------------------------ 2(x+y)-x=0 { . 2(x+y)-y=3 2x + 2y -x =0 x+2y=0 x= -2y -------(1) 2x+2y-y=3 2x+y=3 x= 3-y/2 ------(2) 把(1)入(2) -2y=3-y/2 -4y=3-y -3y =3 y= -1 把y= -1 入(1) x= -2( -1) x=2
其他解答:
文章標籤
全站熱搜
留言列表
