1题答案是4.
2.原式=√(145+24)(145-24)
=√169×121
=13×11
=143
原式=(2√7-2√3+√7)×√7+2√21
=2×7-2√21+7+2√21
=21
原式=√2×2√2-√2×√3+3√3×2√2-3√3×√3
=4-√6+6√6-9
=-5-5√6
1题答案是4.
2.原式=√(145+24)(145-24)
=√169×121
=13×11
=143
原式=(2√7-2√3+√7)×√7+2√21
=2×7-2√21+7+2√21
=21
原式=√2×2√2-√2×√3+3√3×2√2-3√3×√3
=4-√6+6√6-9
=-5-5√6