14.若︱4x -7︱+
=0,則 4x +3y=?
(A)-1
(B) 1
(C)-15
(D) 15
答案:登入後查看
統計: A(502), B(44), C(31), D(31), E(0) #816515
統計: A(502), B(44), C(31), D(31), E(0) #816515
詳解 (共 4 筆)
#1651219
4x - 7 = 0 , 4x = 7
3y + 8 = 0 , 3y = -8
4x + 3y = 7 + (-8) = -1
7
0
#1135505
令︱4x -7︱=0 得x=7/4;令(3Y+8)1/2=0 得y=(-8/3),代入式中可求得答案(A)
3
0