Question

设f(x)=2x−1，求f(0)，f(2) ，f(−5)

Answer 1

问：设f(x)=2x−1，求f(0)，f(2) ，f(−5)

答：f(x)=2x−1，那么f(0)=-1，f(2) =3，f(−5)=-11

答：f(x)=2x−1，那么f(0)=2×0-1=-1f(2) =2×2-1=3f(−5)=2×（-5）-1=-11直接代入求值

答：一次函数一般地，形如y=kx+b（k，b是常数，k≠0）的函数，叫做一次函数．当b=0时，y=kx+b即y=kx，所以说正比例函数是一种特殊的一次函数．【注意】正比例函数是一次函数的特例，正比例函数一定是一次函数，但一次函数不一定是正比例函数．一次函数解析式 y=kx+b 的结构特征（1）k是常数， k≠0 ；（2）自变量x的次数是1；（3）常数项b可以为任意实数．

答：第一题选择B，第二题选择B

问：还有好多题呢

答：题目比较多，可以考虑这个服务，我可以详细解答

问：79.9太贵了，还有便宜的吗

问：还有在便宜的吗

答：主要是一套试卷题目比较多，问答题都需要写过程

问：36)Weoften on the playsround.A.play B.playing C.plays D.played37) he brush his teeth every morning?A.Do B.Does C.Did D.Doing38)What Amy and Sara do after school?A. do B.does C.did D.doing39)Tom and his sister the same hobby.A.have B.has C.had D.having40)My dosruns fast， he?A. does B. doesn't C.did D didn't41)Chrissy doesn't herparty at home.A. enjoy B.enjoys C.enjoying D.enjoyed42)He，togetherwith his parents， and dinnerat home on Saturdays.A. cook， have

答：36)Weoften A on the playsround.37) B he brush his teeth every morning?38)What A Amy and Sara do after school?39)Tom and his sister A the same hobby.40)My dosruns fast，B he?41)Chrissy doesn't A herparty at home.42)He，togetherwith his parents， cooks and has dinnerat home on Saturdays.