1,计算:√(13+2√7+2√5+2√35) -(3√7+4√6+√3)/(√42+√21+3√2+6)=___________________
问题描述：
1,计算:√(13+2√7+2√5+2√35) -(3√7+4√6+√3)/(√42+√21+3√2+6)=___________________
答
√(13+2√7+2√5+2√35)-(3√7+4√6+√3)/(√42+√21+3√2+6)=√(√7+√5+1)² - (√3√21+4√3√2+√3)/[√2√21+√21+3√2+3√2√2]=√7+√5+1 - √3(√21+4√2+1)/[(√2+1)√21+3(√2+1)√2]=√7+√5+1 - √3...