1. Tínha, $2\sqrt{(-3)^{6}}+3\sqrt{(-2)^{4}}$b, $\sqrt{(2+\sqrt{3})^{2}}$c, $3.\sqrt{(-0...
Câu hỏi:
1. Tính
a, $2\sqrt{(-3)^{6}}+3\sqrt{(-2)^{4}}$
b, $\sqrt{(2+\sqrt{3})^{2}}$
c, $3.\sqrt{(-0,2)^{2}}-(\sqrt{2})^{2}+3\sqrt{(-3)^{2}}$
d, $(\sqrt{5})^{2}+2\sqrt{(-\frac{1}{2})^{2}}-3\sqrt{(-\frac{1}{3})^{2}}$
Câu trả lời:
Người trả lời: GV. Đỗ Đăng Đức
a, $2\sqrt{(-3)^{6}}+3\sqrt{(-2)^{4}}$ = $2\sqrt{[(-3)^{3}]^{2}}+3\sqrt{[(-2)^{2}]^{2}}$= 2.|$(-3)^{3}$| + 3.|$(-2)^{2}$| = 2.27 + 3.4 = 66b, $\sqrt{(2+\sqrt{3})^{2}}$ = |$2+\sqrt{3}$| = $2+\sqrt{3}$c, $3.\sqrt{(-0,2)^{2}}-(\sqrt{2})^{2}+3\sqrt{(-3)^{2}}$ = 3.|-0.2| - $\sqrt{2}$ + 3.|-3| = 3.0.2 - $\sqrt{2}$ + 3.3 = 9.6 - $\sqrt{2}$d, $(\sqrt{5})^{2}+2\sqrt{(-\frac{1}{2})^{2}}-3\sqrt{(-\frac{1}{3})^{2}}$ = $\sqrt{5}+2\left | -\frac{1}{2} \right |-3\left | -\frac{1}{3} \right |$ = $\sqrt{5}-2\frac{1}{2}-3\frac{1}{3}$ = $\sqrt{5}$ Vậy kết quả của các phép tính là:a) $66$b) $2+\sqrt{3}$c) $9.6 - \sqrt{2}$d) $\sqrt{5}$
Câu hỏi liên quan:
{ "content1": "a. $\sqrt{(-3)^6}=\sqrt{729}=27$, $2\sqrt{(-3)^6}=2*27=54$; $\sqrt{(-2)^4}=\sqrt{16}=4$, $3\sqrt{(-2)^4}=3*4=12$", "content2": "b. $\sqrt{(2+\sqrt{3})^{2}}=2+\sqrt{3}$", "content3": "c. $\sqrt{(-0,2)^{2}}=\sqrt{0,04}=0,2$, $\sqrt{2}=1,41$, $3\sqrt{(-0,2)^{2}}-(\sqrt{2})^{2}+3\sqrt{(-3)^{2}}=0,6-1,41+9=7,19$", "content4": "d. $(\sqrt{5})^{2}=5$, $\sqrt{(-\frac{1}{2})^{2}}=\sqrt{\frac{1}{4}}=0,5$, $\sqrt{(-\frac{1}{3})^{2}}=\sqrt{\frac{1}{9}}=0,33$, $5+2*0,5-3*0,33=5+1-0,99=5,01$", "content5": "e. $2\sqrt{(-3)^6}+3\sqrt{(-2)^4}=2*27+3*4=54+12=66$", "content6": "f. $\sqrt{(2+\sqrt{3})^{2}}=\sqrt{4+2\sqrt{3}+\sqrt{3}^{2}}=\sqrt{4+2\sqrt{3}+3}= \sqrt{7+2\sqrt{3}}$"}