t(5-t)(t2+25) ————— =3t 这个方程怎么解?尽快!25是25分之t（5-t)(t2+25） =3t

t(5-t)(t2+25) ————— =3t 这个方程怎么解?尽快!25是25分之t（5-t)(t2+25） =3t 如何由(v2 –v1 )t 1=(v1+v2)t2=v1(t1 +t2 ) 1 1 1 求出——+—— = —— v2-v1 v2 +v1 v1如何由(v2 –v1 )t 1=(v1+v2)t2=v1(t1 +t2 )1 1 1 求出——+—— = ——v2-v1 v2 +v1 v1 某质点的位移随时间变化的关系式是：s = 4t —2t2,s 和t的单位分别是m和s, 某质点的位移随时间变化的关系式是：s = 4t —2t2,s 和t的单位分别是m和s, 公路上行驶的汽车急刹车时的行驶路程s(m)与时间t(s)的函数关系式为s=20t—5t2,当遇到紧急情况时,司机急刹车,但由于惯性汽车要滑行___________m才能停下来.那个5t2是5乘以t的平方 5．某质点的位移随时间变化的关系式是：s = 4t —2t2,s 和t的单位分别是m和s, 若 f(t)=2t2+2t2+5t+5t,证明f(t)=f(1t) [ t2-2 ( t-3 )] T-ara *——* 2t+3t3次方一(3t2次方+5t一t2次方) 有关V—T,S---T图像曲线运动的V—T,S---T图像是什么? 1.——sorry Joe.I didn't mean to.——Don't call me Joe.I'm Mr Parker to you.You ( ) forget it!A.do B.didn't C.did D.don't2.——Alice,you feed the bird,( ——But I fed it yesterday.A.do you B.will you?C.didn't you D.don't you请解释原因. 一 选择填空 .1.—Will people live to be 300 years old?—__________.A.No,they are aren't B.No,they won't C,No they don't D.No ,they can't2.—I will see you again______,A a day B every day C one day D everyday3.—I hope your dream will ______, 几道英语单选,在线等```````~1、——Don’t forget to tell me him the good news._____Of course I_______.A:don't B:won't C:will D:haven't2.---Did you _____what the teacher said?---Not really.He spoke a little fast .A.prefer B.listen to C.cat （1）Jack like Beijing Opera?Yes,he often tells（2）,“Beijing Opera is really interesting!——My father like it,too.”He wants to be a Beijing Opera artist!1 A Isn't B Don't C Doesn't D Are't2 A I B my C me D she 选择,主要是（1）不 —Johnny,you______ play with matches,you______burn yourself.A.won't ; can't B.mustn't ; may C.shouldn't ; must D.can't ; shouldn't 已知t=-2分之一求代数式2(t方_t—1)-(t方-t-|)+(t方-t-1)的值要过程? 1、—Is that Bill's ruler?—_______A.Yes,that is B.No,it isn't C.No,that isn't2、Here're photos_____our class.A.of B.under C.on