a) \(\sqrt{13^2-12^2}\)=\(\sqrt{\left(13-12\right)\left(13+12\right)}\)=\(\sqrt{1x25}\)=5
Câu a: Ta có:
√132−122=√(13+12)(13−12)132−122=(13+12)(13−12)
=√25.1=√25=25.1=25
=√52=|5|=5=52=|5|=5.
Câu b: Ta có:
√172−82=√(17+8)(17−8)172−82=(17+8)(17−8)
=√25.9=√25.√9=25.9=25.9
=√52.√32=|5|.|3|=52.32=|5|.|3|.
=5.3=15=5.3=15.
Câu c: Ta có:
√1172−1082=√(117−108)(117+108)1172−1082=(117−108)(117+108)
=√9.225=9.225 =√9.√225=9.225
=√32.√152=|3|.|15|=32.152=|3|.|15|
=3.15=45=3.15=45.
Câu d: Ta có:
√3132−3122=√(313−312)(313+312)3132−3122=(313−312)(313+312)
=√1.625=√625=1.625=625
=√252=|25|=25=252=|25|=25.
a, \(\sqrt{13^2-12^2}=\sqrt{\left(13-12\right)\left(13+12\right)}=\sqrt{1.25}=5\)
b, \(\sqrt{17^2-8^2}=\sqrt{\left(17-8\right)\left(17+8\right)}=\sqrt{9.25}=3.5=15\)
c, \(\sqrt{117^2-108^2}=\sqrt{\left(117-108\right)\left(117+108\right)}=\sqrt{9.225}=3.15=45\)
d, \(\sqrt{313^2-312^2}=\sqrt{\left(313-312\right)\left(313+312\right)}=\sqrt{1.625}=25\)
a)5
b)15
c)45
d)25
a) Ta có:
.
b) Ta có:
.
c) Ta có:
$=\sqrt{9.225}
.
d) Ta có:
.
a) 5
b)15
c) 45
d) 25
Câu a: Ta có:
.
Câu b: Ta có:
.
.
Câu c: Ta có:
.
Câu d: Ta có:
a) Ta có:
.
b) Ta có:
.
c) Ta có:
$=\sqrt{9.225}
.
d) Ta có:
.
a) \(\sqrt{13^2-12^2}=\sqrt{25.1}=5\)
b) \(\sqrt{17^2-8^2}=\sqrt{25.9}=15\)
c)\(\sqrt{117^2-108^2}=\sqrt{3^2}.\sqrt{15^2=45}\)
d) \(\sqrt{313^2-312^2}=\sqrt{625}=25\)
a) \(\sqrt{13^2-12^2}=\sqrt{\left(13-12\right)\left(13+12\right)}=\sqrt{25}=5\)
b) \(\sqrt{17^2-8^2}=\sqrt{\left(17-8\right)\left(17+8\right)}=\sqrt{9.25}=3.4=12\)
c) \(\sqrt{117^2-108^2}=\sqrt{\left(117-108\right)\left(117+108\right)}=\sqrt{9.225}=3.15=45\)
d) \(\sqrt{313^2-312^2}=\sqrt{\left(313-312\right)\left(313+312\right)}=\sqrt{1.625}=25\)
a) 5
b) 15
c) 45
d) 25
a) 5
b) 15
c) 45
d) 25
a=5
b=15
c=45
d=25
a.\(\sqrt{0,36a^2}vớia< 0\)
=\(\sqrt{1,36}.\sqrt{a^2}=-0,6.\left|a\right|=-0,6a\left(via< 0\right)\)
b.\(\sqrt{a^4\left(3-a\right)^2}=\sqrt{a^4}\sqrt{\left(3-a\right)^2}=a^2.\left|3-a\right|=a^2\left(a-3\right)\)
a)\(\sqrt{13^2-12^2}\)
=\(\sqrt{\left(13+12\right)\left(13-12\right)}\)
=\(\sqrt{25}=5\)
b)\(\sqrt{17^2-8^2}\)
=\(\sqrt{\left(17+8\right)\left(17-8\right)}\)
=\(\sqrt{25.9}\)
=\(\sqrt{25}.\sqrt{9}\)
=\(5.3=15\)
c)\(\sqrt{117^2-108^2}\)
=\(\sqrt{\left(117+108\right)\left(117-108\right)}\)
=\(\sqrt{225.9}\)=\(\sqrt{2025}=45\)
d)\(\sqrt{313^2-312^2}\)
=\(\sqrt{\left(313+312\right)\left(313-312\right)}\)
=\(\sqrt{625}\)=25
a) Ta có:
.
b) Ta có:
.
c) Ta có:
=\(\sqrt{9.225}\)
.
d) Ta có:
.
a) Ta
.
b) Ta
.
c) Ta có:
$=\sqrt{9.225}=\sqrt{9}.\sqrt{225}$
.
d) Ta
.
a) Ta có:
.
b) Ta có:
.
c) Ta có:
$=\sqrt{9.225}
.
d) Ta có:
.