Question

①6(7+1)(7*7+1)(7*7*7*7+1)(7*7*7*7*7*7*7*7+1)+1

②1.345*0.345*2.69-1.345*1.345*1.345-1.345*0.345*0.345
要求过程，详细啊 好的会提悬赏！！！
还有一题：正整数a,b,c满足不等式a*a+b*b+c*c+42＜ab+9b+8c

Answer 1

1)6(7+1)(7*7+1)(7*7*7*7+1)(7*7*7*7*7*7*7*7+1)+1
=(7-1)(7+1)(7*7+1)(7*7*7*7+1)(7*7*7*7*7*7*7*7+1)+1
=(7*7-1)7*7+1)(7*7*7*7+1)(7*7*7*7*7*7*7*7+1)+1
=(7^16-1)+1=7^16
2).1.345*0.345*2.69-1.345*1.345*1.345-1.345*0.345*0.345
设X=0.345,则有 1.345=1+X,2.69=2(1+X)
所以原式=(1+X)*X*2(1+X)-(1+X)(1+X)(1+X)-(1+X)*X*X
=(1+X)(2X+2X^2-1-2X-X^2-X^2)=(1+X)(-1)=-(1+X)=-1.345

Answer 2

1)6(7+1)(7*7+1)(7*7*7*7+1)(7*7*7*7*7*7*7*7+1)+1
=(7-1)(7+1)(7*7+1)(7*7*7*7+1)(7*7*7*7*7*7*7*7+1)+1
=(7*7-1)7*7+1)(7*7*7*7+1)(7*7*7*7*7*7*7*7+1)+1
=(7^16-1)+1=7^16
2).1.345*0.345*2.69-1.345*1.345*1.345-1.345*0.345*0.345
设X=0.345,则有 1.345=1+X,2.69=2(1+X)
所以原式=(1+X)*X*2(1+X)-(1+X)(1+X)(1+X)-(1+X)*X*X
=(1+X)(2X+2X^2-1-2X-X^2-X^2)=(1+X)(-1)=-(1+X)=-1.345
3).想求什么?

Answer 3

(7-1)(7+1)(7*7+1)(7*7*7*7+1)(7*7*7*7*7*7*7*7+1)＝7的16次方减1
1.345*0.345*2.69-1.345*1.345*1.345-1.345*0.345*0.345＝1.345*0.345*2.69-(1.345*1.345*1.345+1.345*0.345*0.345)＝0