23666: HW 2
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HelmutKnaust (Talk | contribs) (Created page with "'''Problem 6.''' Is the statement $\quad\exists !\,x\in\mathbb{R} : (x-2=\sqrt{x+7}) \quad$ true or false? Prove your conjecture. '''Problem 7.''' Let $x$, $y$, and $z$ be na...") |
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− | '''Problem 6.''' Is the statement $\quad\exists !\,x\in\mathbb{R} : (x-2=\sqrt{x+7}) \quad$ true or false? | + | '''Problem 6.''' Is the statement $\quad\exists !\,x\in\mathbb{R} : (\ x-2=\sqrt{x+7}\ ) \quad$ true or false? |
Prove your conjecture. | Prove your conjecture. | ||
Latest revision as of 17:41, 6 February 2019
Problem 6. Is the statement $\quad\exists !\,x\in\mathbb{R} : (\ x-2=\sqrt{x+7}\ ) \quad$ true or false? Prove your conjecture.
Problem 7. Let $x$, $y$, and $z$ be natural numbers. Prove or disprove: If $x+y$ is even and $y+z$ is even, then $x+z$ is even.
Problem 8. Let $x$, $y$, and $z$ be natural numbers. Prove or disprove: If $x+y$ is odd and $y+z$ is odd, then $x+z$ is odd.
Problem 9. Let $x$ be a natural number. Prove or disprove: If $x^2$ is divisible by 27, then $x$ is divisible by 9.
Problem 10. Let $n$ be a natural number. Show that $\sqrt{n}$ is a natural number if and only if $n=k^2$ for some natural number $k$.