题目

解方程： （1） （2） 答案：解：移项得 −4y−8y=3−9 合并得 −12y=−6系数化为1得 y=12 解：去分母得 21x+3(3x+10)= 21−7(1−2x) 去括号得 21x+9x+30=21−7+14x移项得 21x+9x−14x=21−7−30合并得 16x=−16系数化为1得 x=−1Pat Brown went to her bank to ask for an ATM card. It looks like a credit card. A few weeks later, the bank posted her a card and a four number personal identification number (PIN) .Her PIN is 1234。As Pat was getting ready for bed one night, she remembered that she had only＄2 in her bag. The next day she had to pay＄10 for a lunch for a co-worker. She didn’t want to get up early to go to the bank. So she went to the bank that night. She used her ATM card to withdraw (take out) ＄50 from her checking account.These are the steps she followed to withdraw money. First, she put her card in the lower slot on the right side of the machine. She made sure her card was facing the right way. Second, the computer screen (window) said,“Please enter (put in) your PIN.”Pat pressed the numbers 1,2,3,4. Next the screed said,“Please select the type of transaction you want by pressing the correct keys.”Pat pressed the bottom key for withdrawing money.Then the screen said, “From which account?” The choices it gave were “Checking”, “Saving”, and “Money market”. Pat pushed the key for “Checking”.Next, the screen said,“Please select (choose) amount of transaction.”Pat pushed the number“5”and then“0”three times, until the screed read,“50.00.”The screen then read,“Please wait.”In less than a minute, it read,“Please lift (rise) the lid and take your money.”Pat lifted the lid marked “Withdraw”. She counted her $50 to make sure the ATM hadn’t made a mistake. Then she waited for her withdrawal slip to come out of the slot at the upper right corner of the machine. Pat checked the slip to make sure it was correct. Then her ATM card was returned through the card slot. She put it in her bag and walked away. If Pat had made a mistake at any point by pressing the wrong button (number), she could have pressed “Cancel”and started over again.53. What did Pat do immediately after choosing the account?A. Selected whether to withdraw, deposit, of transfer money.B. Lifted the lid and removed her money.C. Selected the amount of money she wanted to withdraw.D. Got back her ATM card.54. When did Pat enter her PIN?A. Right after inserting her card.                                B. Right before selecting the account. C. Right before selecting the amount of money.            D. Right after selecting withdrawal.55. When did Pat select the type of transaction?A. Right after selecting which account she wanted.B. Right before receiving her withdrawal slip.C. Right before selecting the amount.    D. Right after recording her PIN.56.What did Pat do when the screed said,“Please lift the lid …”?A. Got out her card.                               B. Took her $50.C. Selected the type of transaction she wanted.           D. Picked up her withdrawal slip.