7.点P(5,-4)关于y轴对称点是( )
0 282148 282156 282162 282166 282172 282174 282178 282184 282186 282192 282198 282202 282204 282208 282214 282216 282222 282226 282228 282232 282234 282238 282240 282242 282243 282244 282246 282247 282248 282250 282252 282256 282258 282262 282264 282268 282274 282276 282282 282286 282288 282292 282298 282304 282306 282312 282316 282318 282324 282328 282334 282342 366461
| A. | (5,4) | B. | (5,-4) | C. | (4,-5) | D. | (-5,-4) |