Question

Tentukan hasil dari (2√3–5√7)(2√3–5√7)= pakai cara

Answer 1

Answer:

solving the expression $\left(2\sqrt{3}-5\sqrt{7}\right)\:\left(2\sqrt{3}-5\sqrt{7}\right)$ we get $\mathbf{187+20\sqrt{21}}$

Step-by-step explanation:

We need to solve: $\left(2\sqrt{3}-5\sqrt{7}\right)\:\left(2\sqrt{3}-5\sqrt{7}\right)$

We can write it as:

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

We can use formula: $a^2-b^2=a^2-2ab+b^2$

$=\left(2\sqrt{3})^2-2(2\sqrt{3})(-5\sqrt{7})+(-5\sqrt{7}\right)^2\\=4(3)+20\sqrt{3}\sqrt{7}+25(7)\\=12+20\sqrt{3\times 7}+175\\=187+20\sqrt{21}$

So, solving the expression $\left(2\sqrt{3}-5\sqrt{7}\right)\:\left(2\sqrt{3}-5\sqrt{7}\right)$ we get $\mathbf{187+20\sqrt{21}}$