8.已知等腰三角形的两边长x,y满足方程组$\left\{\begin{array}{l}{4x+y=18}\\{x-2y=-9}\end{array}\right.$,则此等腰三角形的周长为( )
| A. | 12 | B. | 12或14 | C. | 15 | D. | 15或14 |
7.若不等式组$\left\{\begin{array}{l}{x≥-b}\\{1-2x>x-2}\end{array}\right.$无解,则实数b的取值范围是( )
| A. | b≤-1 | B. | b≥-1 | C. | b<-1 | D. | b>-1 |
6.线段a,b,c的长度比为1:$\sqrt{2}$:1,若以a,b,c为边组成三角形,则三角形的形状是( )
0 297008 297016 297022 297026 297032 297034 297038 297044 297046 297052 297058 297062 297064 297068 297074 297076 297082 297086 297088 297092 297094 297098 297100 297102 297103 297104 297106 297107 297108 297110 297112 297116 297118 297122 297124 297128 297134 297136 297142 297146 297148 297152 297158 297164 297166 297172 297176 297178 297184 297188 297194 297202 366461
| A. | 等腰三角形 | B. | 等腰直角三角形 | C. | 直角三角形 | D. | 无法组成三角形 |