Question

$frac{2* sqrt{2+x}}{15}$  при x=-1.19

$frac{a-b}{a+b} - frac{a+b}{a-b}$

$frac{1}{a} - sqrt{c}$  при a=0.04 и c=0.64

Answer 1

$1) frac{2* sqrt{2-1.19} }{15} = frac{2* sqrt{0.81} }{15} = frac{2*0.9}{15} = frac{1.8}{15} =0.12 \ \ 2) frac{a-b}{a+b} - frac{a+b}{a-b} = frac{(a-b)(a-b)-(a+b)(a+b)}{a ^{2} -b ^{2} } = frac{a ^{2} +b ^{2} -2ab- a^{2} -b ^{2} -2ab}{a ^{2} -b ^{2} } = \ =- frac{4ab}{a ^{2} -b ^{2} } \ \ 3) frac{1}{0.04} - sqrt{0.64} =25-0.8=24.2$