<span>а)√18-3√32+2√8-√72 = 3</span>√2 - 12√2 + 4√2 - 6√2 = -11√2<span>
б)0,4√12-0,9√27+1,3√75 = 0,8</span>√3 - 2,7√3 + 6,5√3 = 4,6√3 <span>
в)-2√80+√320-4√20+√45 = -8</span>√5 + 8√5 - 8√5 + 3√5 = -5√5<span>
г)
</span>
![\sqrt{0,8}+ \sqrt{3,2}+ \sqrt{5}-10 \sqrt{7,2} = \sqrt{ \frac{4}{5} } +\sqrt{ \frac{16}{5} }+ \sqrt{5}-10 \sqrt{ \frac{36}{5} }= \\= \frac{2}{ \sqrt{5} } + \frac{4}{ \sqrt{5} }+ \sqrt{5}-10 *\frac{6}{ \sqrt{5} } = \frac{2 \sqrt{5} }{5} +\frac{4 \sqrt{5} }{5} + \frac{ 5\sqrt{5} }{5} - \frac{60 \sqrt{5} }{5} =-\frac{49 \sqrt{5} }{5}](https://tex.z-dn.net/?f=+%5Csqrt%7B0%2C8%7D%2B+%5Csqrt%7B3%2C2%7D%2B+%5Csqrt%7B5%7D-10+%5Csqrt%7B7%2C2%7D+%3D+%5Csqrt%7B+%5Cfrac%7B4%7D%7B5%7D+%7D++++%2B%5Csqrt%7B+%5Cfrac%7B16%7D%7B5%7D+%7D%2B+%5Csqrt%7B5%7D-10+%5Csqrt%7B+%5Cfrac%7B36%7D%7B5%7D+%7D%3D+%5C%5C%3D+%5Cfrac%7B2%7D%7B+%5Csqrt%7B5%7D+%7D+++%2B+%5Cfrac%7B4%7D%7B+%5Csqrt%7B5%7D+%7D%2B+%5Csqrt%7B5%7D-10+%2A%5Cfrac%7B6%7D%7B+%5Csqrt%7B5%7D+%7D+%3D+%5Cfrac%7B2+%5Csqrt%7B5%7D+%7D%7B5%7D+%2B%5Cfrac%7B4+%5Csqrt%7B5%7D+%7D%7B5%7D+%2B+%5Cfrac%7B+5%5Csqrt%7B5%7D+%7D%7B5%7D++-+%5Cfrac%7B60+%5Csqrt%7B5%7D+%7D%7B5%7D+%3D-%5Cfrac%7B49+%5Csqrt%7B5%7D+%7D%7B5%7D+)
1)переводим 1/4 в десятичную дробь получаем 0.25
2) вычитаем 0.25-0.7=-0.45
или можешь перевести 0.7
получается 1/4-7/10=-9/20