, 3 4 8 9. , ? .

. , . /.

20 5 . , ?

12 5 , ?

### B5 #2335

$$sin \frac{\pi x}{2}=x^{2}+6x+10$$

### B6 #2336

$$ABC$$ $$AK$$ $$CP$$ $$Q$$. , $$B$$ $$ABC$$, , $$AK=12$$, $$CP=9$$.

### B7 #2337

$$f(x)=x^{2} - 4 \left | x \right | +3$$. $$[-1; 3,5]$$.

, . , 12.

### B9 #2339

$$81^{log_{3} \sqrt{2}}-log_{6}9-log_{\frac{1}{\sqrt{6}}} \frac{1}{2}+log_{2}6-log_{2}3$$.

### B10 #2340

( ) ( ) $$T(t)=T_{0}+at+bt^{2}$$, $$T_{0}=1200$$, $$a=48 /$$, $$b= 0,4 /^{2}$$. , $$2000$$ , . ( ), .

### B11 #2341

, 3 . , 100 . . /.

### B12 #2342

$$\sqrt{(x-1)^{2}+(y-5)^{2}}+\sqrt{(x-9)^{2}+(y+10)^{2}}$$

### B13 #2343

$$sin(2^{x})=1$$, $$\left | 2^{x}-1 \right | + \left | 2^{x}-8 \right | \leqslant 7$$

### B14 #2344

$$S$$ $$SABC$$ .
) , $$S$$, $$ABC$$ , ( ), .
) $$SABC$$, , $$SA=2, SB=3, SC=4$$.

### B15 #2345

$$x^{2}+x \sqrt{3-3x^{2}} \geqslant 0,5 + x$$

### B16 #2346

$$ABCD$$, $$B$$ , $$BC$$ $$AD$$ , : 1) $$B$$; 2) $$C)$$; 3) , $$AB)$$ $$CD$$.
) , .
) $$ABCD$$, , $$BC=8, AD=18$$.

### B17 #2347

, , $$A$$ $$B$$, 40 . 4 /, 30 /. 6 /, 20 /. $$A$$ $$B$$?
( )

### B18 #2348

$$p_{2}$$ $$p_{1}$$, $$y=ax^{2} (a>0)$$, $$T(b; ab^{2}), b>0$$. : $$p_{1}$$ $$A_{1}$$, $$p_{2}$$ $$A_{2}$$ , $$A_{1}A_{2}T$$ . $$p_1$$, $$T$$, $$A_{1}A_{2}$$ $$K$$. , $$K$$ $$A_{1}A_{2}$$.

### B19 #2349

:
) $$[2x] = {7x}$$;
) $$[2x] = 7x$$;
) $$2x = {7x}$$.

[a] , .. , ; {a} , .. {a} = [a].