幫我計左而幾條數佢.........
1 (-12)+(-7)*4=
2.if y =3x二次 - 4X, when x= -2 y=__________
3.if 2x+7/9 = 3 , x=____________
幫下我手喇.....
2007-08-07 11:05 pm
回答 (4)
2007-08-07 11:33 pm
✔ 最佳答案
1.(-12)+(-7)*4= -12 -28
= -40
2.
if y =3x^2 - 4x
when x= -2,
y= 3(-2)^2 - 4(-2)
= 3*4 -(-8)
= 12+8 = 20
3.
2x+7/9 = 3
18x + 7 = 27
18x = 20
x = 20/18
= 10/9
2007-08-08 1:51 am
1. -12+(-28)= -40
2. if y=3x^2-4x, when x= -2 =>> y=3(-2)^2-4(-2)=12+8=20
3. if 2x=20/9, =>> x=20/18=10/9
2. if y=3x^2-4x, when x= -2 =>> y=3(-2)^2-4(-2)=12+8=20
3. if 2x=20/9, =>> x=20/18=10/9
2007-08-07 11:34 pm
1) -12 + (-7)4
= -12 + (-28)
= -12-28
= -40
2) 想問你, x= -2y 定係 x=-2
如果係後者:
y=3x 二次 -4x
=3(-2)二次 - 4(-2)
=3(4) - (-8)
=12+8
=20
3) 2x +7/9=3
2x =3 - 7/9
2x =27/9 - 7/9
2x = 20/9
x = 20/9 / 2 ( 這個看起來好像好難明，我用中文說一次吧。"20 over 9 除以 2")
x = 10/9
希望幫到你啦~
= -12 + (-28)
= -12-28
= -40
2) 想問你, x= -2y 定係 x=-2
如果係後者:
y=3x 二次 -4x
=3(-2)二次 - 4(-2)
=3(4) - (-8)
=12+8
=20
3) 2x +7/9=3
2x =3 - 7/9
2x =27/9 - 7/9
2x = 20/9
x = 20/9 / 2 ( 這個看起來好像好難明，我用中文說一次吧。"20 over 9 除以 2")
x = 10/9
希望幫到你啦~
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原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070807000051KK02725