Câu hỏi của Pham Ngoc Diep

Question

Bài 1.  Tìm số nguyên x biết:a) x – 15 = – 21;b) 42 – x = – 7;c) 12 – (30 – x) = – 23;d) 31 – (17 + x) = 18.Mik sẽ tick nha

Lấp La Lấp Lánh · Accepted Answer

a) $x-15=-21$$\Rightarrow x=-21+15=-6$b) $42-x=-7$$\Rightarrow x=42+7=49$c) $12-\left(30-x\right)=-23$$\Rightarrow30-x=12+23=35$$\Rightarrow x=30+35=65$d) $31-\left(17+x\right)=18$$\Rightarrow17+x=31-18=13$$\Rightarrow x=13-17=-4$Câu trả lời: a) $x-15=-21$$\Rightarrow x=-21+15=-6$b) $42-x=-7$$\Rightarrow x=42+7=49$c) $12-\left(30-x\right)=-23$$\Rightarrow30-x=12+23=35$$\Rightarrow x=30+35=65$d) $31-\left(17+x\right)=18$$\Rightarrow17+x=31-18=13$$\Rightarrow x=13-17=-4$

Vũ Trọng Hiếu · Answer

a) x−15=−21x−15=−21⇒x=−21+15=−6⇒x=−21+15=−6b) 42−x=−742−x=−7x=42+7=49⇒x=42+7=49c) 12−(30−x)=−2312−(30−x)=−2330−x=12+23=35⇒30−x=12+23=35x=30+35=65⇒x=30+35=65d) 31−(17+x)=1831−(17+x)=1817+x=31−18=13⇒17+x=31−18=13x=13−17=−4Câu trả lời: a) x−15=−21x−15=−21⇒x=−21+15=−6⇒x=−21+15=−6b) 42−x=−742−x=−7x=42+7=49⇒x=42+7=49c) 12−(30−x)=−2312−(30−x)=−2330−x=12+23=35⇒30−x=12+23=35x=30+35=65⇒x=30+35=65d) 31−(17+x)=1831−(17+x)=1817+x=31−18=13⇒17+x=31−18=13x=13−17=−4

a) x+ 118 =218	b) 18 – x =-17	c) (-18) – x =-17
d)124 +(118 – x)=217	e) (3x – 6).3 = 3⁴	g) 23.(42 – x) = 46
h) 84 – (3x + 8) = 34	i) 3(2x + 1) -19 = 14	k) 6x – 302 = 2³.5
m) (x -1)²= 81	n) 2^x+1- 5 =27	m) 2^x+ 2^x+1+ 2^x+2 = 56

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Khoá học trên OLM (olm.vn)

a) x – 15 = – 21;	b) 42 – x = – 7;
c) 12 – (30 – x) = – 23;	d) 31 – (17 + x) = 18.