Câu hỏi của Lương Tuệ Mẫn

Question

Thực hiện phép tính:
a) $(\sqrt12+\sqrt3)(12+3)$ $(\sqrt27-\sqrt3)(27-3)$
b) $(...$

✿ Hương ➻❥ · Accepted Answer

$\left(\sqrt{12}+\sqrt{3}\right)\left(12+3\right)\left(\sqrt{27}-\sqrt{3}\right)\left(27-3\right)$

$=3\sqrt{3}.15.2\sqrt{3}.24$

= $3\sqrt{3}.2\sqrt{3}.15.24$

= $18.15.24=6480$

Câu trả lời:

$\left(\sqrt{12}+\sqrt{3}\right)\left(12+3\right)\left(\sqrt{27}-\sqrt{3}\right)\left(27-3\right)$

$=3\sqrt{3}.15.2\sqrt{3}.24$

= $3\sqrt{3}.2\sqrt{3}.15.24$

= $18.15.24=6480$

✿ Hương ➻❥ · Answer

$\left(5\sqrt{3}-2\sqrt{7}\right)\left(5\sqrt{3}+2\sqrt{7}\right)\left(53-27\right)\left(53+27\right)$

= $\left(\left(5\sqrt{3}\right)^2-\left(2\sqrt{7}\right)^2\right).26.80$

= $\left(75-28\right).26.80$

= 47.26.80 = 97760

Câu trả lời:

$\left(5\sqrt{3}-2\sqrt{7}\right)\left(5\sqrt{3}+2\sqrt{7}\right)\left(53-27\right)\left(53+27\right)$

= $\left(\left(5\sqrt{3}\right)^2-\left(2\sqrt{7}\right)^2\right).26.80$

= $\left(75-28\right).26.80$

= 47.26.80 = 97760