6.若关于x的不等式组$\left\{\begin{array}{l}{n-5x≥0}\\{9x≥2x+m}\end{array}\right.$的解集为-1≤x≤1,则m+n的值是( )
| A. | 2 | B. | -2 | C. | -7 | D. | 5 |
2.
如图,AB∥CD,EF与AB、CD分别相交于点E、F,EP⊥EF,与∠EFD的平分线FP相交于点P,且∠BEP=20°,则∠EPF=( )
| A. | 70° | B. | 65° | C. | 55° | D. | 45° |
1.二元一次方程组$\left\{\begin{array}{l}{x+y=4}\\{x-y=2}\end{array}\right.$的解是( )
| A. | $\left\{\begin{array}{l}{x=1}\\{y=3}\end{array}\right.$ | B. | $\left\{\begin{array}{l}{x=3}\\{y=1}\end{array}\right.$ | C. | $\left\{\begin{array}{l}{x=1}\\{y=-2}\end{array}\right.$ | D. | $\left\{\begin{array}{l}{x=2}\\{y=-1}\end{array}\right.$ |
20.
如图,直线l1∥l2,直线l3与l1,l2分别交于A,B两点,若∠1=65°,则∠2=( )
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| A. | 65° | B. | 75° | C. | 115° | D. | 125° |