Câu hỏi của GraceNotFound

Question

bạn nào làm đc bài 33 trở đi, chỉ caanf1 bài thì mik sẽ tick cho lun nhé undefined

Nguyễn Hoàng Tùng · Accepted Answer

Bài 34:

$a,9.\left(x+28\right)=0\Rightarrow x+28=0\Rightarrow x=-28\ b,\left(27-x\right)\left(x+9\right)=0\Rightarrow\left\{{}\begin{matrix}27-x=0\x+9=0\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=27\x=-9\end{matrix}\right.\ c,\left(-x\right)\left(x-43\right)=0\Rightarrow\left\{{}\begin{matrix}-x=0\x-43=0\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=0\x=43\end{matrix}\right.$

Câu trả lời:

Bài 34:

$a,9.\left(x+28\right)=0\Rightarrow x+28=0\Rightarrow x=-28\ b,\left(27-x\right)\left(x+9\right)=0\Rightarrow\left\{{}\begin{matrix}27-x=0\x+9=0\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=27\x=-9\end{matrix}\right.\ c,\left(-x\right)\left(x-43\right)=0\Rightarrow\left\{{}\begin{matrix}-x=0\x-43=0\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=0\x=43\end{matrix}\right.$

Bà ngoại nghèo khó · Answer

Bài 33
a) (62$-$81) $-$(12$-$59$+$9)

= 62$-$81$-$12$+$59$-$9

= (62$-$12)$+$(59$-$9)$-$81

= 50$+$50$-$81

= 100$-$81

= 19

b) ($-$75)$+$329$+$($-$25)

= [($-$75)$+$($-$25)]$+$329

= $-$100$+$329

= 229

c) 32$-$34$+$36$-$38$+$40$-$42

= (32$-$42)$+$($-$38$+$40)$+$(36$+$34)

= $-$10$+$2$+$70

= (70$-$10)$+$2

= 60$+$2

= 62

d) 92$-$(55$-$8)$+$($-$45)

= 92$-$55$+$8$+$($-$45)

= (92$+$8)$+$[($-$55)$+$($-45$)]

= 100$+$($-$100)

= 0