ແກ້ 19*(sqrt{5}-sqrt{3}+sqrt{2})(sqrt{5}-sqrt{3}-sqrt{2})

$$19 \cdot ( \sqrt { 5 } - \sqrt { 3 } + \sqrt { 2 } ) ( \sqrt { 5 } - \sqrt { 3 } - \sqrt { 2 } )$$

ປະເມີນ

$$114-38\sqrt{15}\approx -33,173367156$$

ຂັ້ນຕອນການແກ້

ໃຊ້ຄຸນສົມບັດການແຈກແຈງເພື່ອຄູນ 19 ດ້ວຍ \sqrt{5}-\sqrt{3}+\sqrt{2}.

$$\left(19\sqrt{5}-19\sqrt{3}+19\sqrt{2}\right)\left(\sqrt{5}-\sqrt{3}-\sqrt{2}\right)$$

ນຳໃຊ້ຄຸນສົມບັດການແຈກຢາຍໂດຍການຄູນແຕ່ລະ 19\sqrt{5}-19\sqrt{3}+19\sqrt{2} ດ້ວຍ \sqrt{5}-\sqrt{3}-\sqrt{2}.

$$19\left(\sqrt{5}\right)^{2}-19\sqrt{3}\sqrt{5}-19\sqrt{5}\sqrt{2}-19\sqrt{3}\sqrt{5}+19\left(\sqrt{3}\right)^{2}+19\sqrt{3}\sqrt{2}+19\sqrt{2}\sqrt{5}-19\sqrt{3}\sqrt{2}-19\left(\sqrt{2}\right)^{2}$$

ຮາກຂອງ \sqrt{5} ແມ່ນ 5.

$$19\times 5-19\sqrt{3}\sqrt{5}-19\sqrt{5}\sqrt{2}-19\sqrt{3}\sqrt{5}+19\left(\sqrt{3}\right)^{2}+19\sqrt{3}\sqrt{2}+19\sqrt{2}\sqrt{5}-19\sqrt{3}\sqrt{2}-19\left(\sqrt{2}\right)^{2}$$

ຄູນ 19 ກັບ 5 ເພື່ອໃຫ້ໄດ້ 95.

$$95-19\sqrt{3}\sqrt{5}-19\sqrt{5}\sqrt{2}-19\sqrt{3}\sqrt{5}+19\left(\sqrt{3}\right)^{2}+19\sqrt{3}\sqrt{2}+19\sqrt{2}\sqrt{5}-19\sqrt{3}\sqrt{2}-19\left(\sqrt{2}\right)^{2}$$

ເພື່ອຄູນ \sqrt{3} ແລະ \sqrt{5}, ໃຫ້ຄູນຈຳນວນພາຍໃຕ້ຮາກຂັ້ນສູງ.

$$95-19\sqrt{15}-19\sqrt{5}\sqrt{2}-19\sqrt{3}\sqrt{5}+19\left(\sqrt{3}\right)^{2}+19\sqrt{3}\sqrt{2}+19\sqrt{2}\sqrt{5}-19\sqrt{3}\sqrt{2}-19\left(\sqrt{2}\right)^{2}$$

ເພື່ອຄູນ \sqrt{5} ແລະ \sqrt{2}, ໃຫ້ຄູນຈຳນວນພາຍໃຕ້ຮາກຂັ້ນສູງ.

$$95-19\sqrt{15}-19\sqrt{10}-19\sqrt{3}\sqrt{5}+19\left(\sqrt{3}\right)^{2}+19\sqrt{3}\sqrt{2}+19\sqrt{2}\sqrt{5}-19\sqrt{3}\sqrt{2}-19\left(\sqrt{2}\right)^{2}$$

ເພື່ອຄູນ \sqrt{3} ແລະ \sqrt{5}, ໃຫ້ຄູນຈຳນວນພາຍໃຕ້ຮາກຂັ້ນສູງ.

$$95-19\sqrt{15}-19\sqrt{10}-19\sqrt{15}+19\left(\sqrt{3}\right)^{2}+19\sqrt{3}\sqrt{2}+19\sqrt{2}\sqrt{5}-19\sqrt{3}\sqrt{2}-19\left(\sqrt{2}\right)^{2}$$

ຮວມ -19\sqrt{15} ແລະ -19\sqrt{15} ເພື່ອຮັບ -38\sqrt{15}.

$$95-38\sqrt{15}-19\sqrt{10}+19\left(\sqrt{3}\right)^{2}+19\sqrt{3}\sqrt{2}+19\sqrt{2}\sqrt{5}-19\sqrt{3}\sqrt{2}-19\left(\sqrt{2}\right)^{2}$$

ຮາກຂອງ \sqrt{3} ແມ່ນ 3.

$$95-38\sqrt{15}-19\sqrt{10}+19\times 3+19\sqrt{3}\sqrt{2}+19\sqrt{2}\sqrt{5}-19\sqrt{3}\sqrt{2}-19\left(\sqrt{2}\right)^{2}$$

ຄູນ 19 ກັບ 3 ເພື່ອໃຫ້ໄດ້ 57.

$$95-38\sqrt{15}-19\sqrt{10}+57+19\sqrt{3}\sqrt{2}+19\sqrt{2}\sqrt{5}-19\sqrt{3}\sqrt{2}-19\left(\sqrt{2}\right)^{2}$$

ເພີ່ມ 95 ແລະ 57 ເພື່ອໃຫ້ໄດ້ 152.

$$152-38\sqrt{15}-19\sqrt{10}+19\sqrt{3}\sqrt{2}+19\sqrt{2}\sqrt{5}-19\sqrt{3}\sqrt{2}-19\left(\sqrt{2}\right)^{2}$$

ເພື່ອຄູນ \sqrt{3} ແລະ \sqrt{2}, ໃຫ້ຄູນຈຳນວນພາຍໃຕ້ຮາກຂັ້ນສູງ.

$$152-38\sqrt{15}-19\sqrt{10}+19\sqrt{6}+19\sqrt{2}\sqrt{5}-19\sqrt{3}\sqrt{2}-19\left(\sqrt{2}\right)^{2}$$

ເພື່ອຄູນ \sqrt{2} ແລະ \sqrt{5}, ໃຫ້ຄູນຈຳນວນພາຍໃຕ້ຮາກຂັ້ນສູງ.

$$152-38\sqrt{15}-19\sqrt{10}+19\sqrt{6}+19\sqrt{10}-19\sqrt{3}\sqrt{2}-19\left(\sqrt{2}\right)^{2}$$

ຮວມ -19\sqrt{10} ແລະ 19\sqrt{10} ເພື່ອຮັບ 0.

$$152-38\sqrt{15}+19\sqrt{6}-19\sqrt{3}\sqrt{2}-19\left(\sqrt{2}\right)^{2}$$

ເພື່ອຄູນ \sqrt{3} ແລະ \sqrt{2}, ໃຫ້ຄູນຈຳນວນພາຍໃຕ້ຮາກຂັ້ນສູງ.

$$152-38\sqrt{15}+19\sqrt{6}-19\sqrt{6}-19\left(\sqrt{2}\right)^{2}$$

ຮວມ 19\sqrt{6} ແລະ -19\sqrt{6} ເພື່ອຮັບ 0.

$$152-38\sqrt{15}-19\left(\sqrt{2}\right)^{2}$$

ຮາກຂອງ \sqrt{2} ແມ່ນ 2.

$$152-38\sqrt{15}-19\times 2$$

ຄູນ -19 ກັບ 2 ເພື່ອໃຫ້ໄດ້ -38.

$$152-38\sqrt{15}-38$$

ລົບ 38 ອອກຈາກ 152 ເພື່ອໃຫ້ໄດ້ 114.

$$114-38\sqrt{15}$$