TEST 15
1.
\(\left.\begin{aligned}2b-c+d=3\\b-2c+2d=7\end{aligned}\right\}\)
\(\Rightarrow b+c-d=?\)
A) \(-10\)B) \(-7\)C) \(-4\)D) \(4\)E) \(10\)
2.
\(\left.\begin{aligned}a\cdot x\cdot y=10\\b\cdot x\cdot y=4\\a+b=7\end{aligned}\right\}\)
\(\Rightarrow x\cdot y=?\)
A) \(2\)B) \(4\)C) \(6\)D) \(7\)E) \(10\)
3.
\(\left.\begin{aligned}a\cdot x=12\\a\cdot y=18\\x+y=10\end{aligned}\right\}\)
\(\Rightarrow a=?\)
A) \(-3\)B) \(-2\)C) \(-1\)D) \(2\)E) \(3\)
4.
\(\left.\begin{aligned}a\cdot x=8\\a\cdot y=6\\x-y=2\end{aligned}\right\}\)
\(\Rightarrow a=?\)
A) \(1\)B) \(2\)C) \(3\)D) \(6\)E) \(8\)
5.
\(x,a,b,c\in\mathbb R\)
\(\left.\begin{aligned}x\cdot a=6\\x\cdot b=10\\x\cdot c=14\\a+b=-8\end{aligned}\right\}\)
\(\Rightarrow c=?\)
A) \(-14\)B) \(-7\)C) \(-2\)D) \(-1\)E) \(1\)
6.
\(x,y,z\in\mathbb R^+\)
\(\left.\begin{aligned}x\cdot y=4\cdot z\\y\cdot z=9\cdot x\end{aligned}\right\}\)
\(\Rightarrow y=?\)
A) \(1\)B) \(2\)C) \(4\)D) \(6\)E) \(9\)
7.
\(\left.\begin{aligned}\samefrac3a+b=2\\\samefrac3b+a=3\end{aligned}\right\}\)
\(\Rightarrow\samefrac ab=?\)
A) \(\samefrac12\)B) \(\samefrac23\)C) \(\samefrac32\)D) \(2\)E) \(3\)
8.
\(\left.\begin{aligned}\samefrac4a+b=2\\\samefrac4b+a=7\end{aligned}\right\}\)
\(\Rightarrow\samefrac ab=?\)
A) \(-2\)B) \(-1\)C) \(1\)D) \(\samefrac72\)E) \(4\)