作业帮计算各式:①4√5+√45-√8+√32=___; ②√4/3 ÷ √8/3 × √8/5=____ ③﹙2√3+√5﹚﹙2√3-√5﹚=____
来源：学生作业帮助网 编辑：作业帮 时间：2024/11/16 13:36:50
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计算各式:①4√5+√45-√8+√32=___; ②√4/3 ÷ √8/3 × √8/5=____ ③﹙2√3+√5﹚﹙2√3-√5﹚=____
计算各式:①4√5+√45-√8+√32=___; ②√4/3 ÷ √8/3 × √8/5=____ ③﹙2√3+√5﹚﹙2√3-√5﹚=____
计算各式:①4√5+√45-√8+√32=___; ②√4/3 ÷ √8/3 × √8/5=____ ③﹙2√3+√5﹚﹙2√3-√5﹚=____
①4√5+√45-√8+√32
=4√5+3√5-2√2+4√2
=7√5+2√2
②√4/3 ÷ √8/3 × √8/5
=2/3÷ 2√2/3× 2√2/5
=2/3×3/2√2× 2√2/5
=1/√2× 2√2/5
=2/5
③﹙2√3+√5﹚﹙2√3-√5﹚
=﹙2√3)^2-(√5﹚^2
;=12-25
=-13
解:
①4√5+√45-√8+√32
=4√5+3√5-2√2+4√2
=7√5+2√2
②√4/3 ÷ √8/3 × √8/5
=√4÷√8 × √8/5
=√4/√8 × √8/5
=√4/5
=2/5
③﹙2√3+√5﹚﹙2√3-√5﹚
=﹙2√3)²-(√5﹚²
=12-25
=-13
我是最先作答的啊，伤心