Bài 1.Tính nhanh
a) 34^2 + 66^2 + 68.66
b) 74^2 + 242 - 48.74
tính nhanh
a)34^2+66^2+68.66
b)74^2+24^2-48.74
a)34^2+66^2+68.66
=34^3+2.34.66+66^2
=(34+66)^2
=100^2=10000
b)74^2+24^2-48.74
=74^2-2.74.24+24^2
=(74-24)^2
=50^2=2500
a) \(34^2+66^2+68.66=34^2+2.34.66+66^2=\left(34+66\right)^2=10000\)
Tính nhanh :
a) 34^4 + 66^2 + 68.66
b) 74^2 + 24^2 - 48.74
A. (34+66)²=100²=10000
B. (74-24)²=50²=2500
Tính nhanh:
a) 342+662+68.66
b)742+242-48.74
a) \(34^2+66^2+68.66=\left(34+66\right)^2=10000\)
b) \(74^2+24^2-48.74=\left(74-24\right)^2=2500\)
Tính nhanh :
a) \(34^2+66^2+68.66\)
b) \(74^2+24^2-48.74\)
Bài giải:
a) 342 + 662 + 68 . 66 = 342 + 2 . 34 . 66 + 662 = (34 + 66)2 = 1002 = 10000.
b) 742 + 242 – 48 . 74 = 742 - 2 . 74 . 24 + 242 = (74 - 24)2
=502 =2500
a) Ta có :
\(34^2+2.34.66+66^2=\left(34+66\right)^2=100^2=10000\)
P/S : Áp dụng hằng đẳng thức: \(\left(a+b\right)^2\)
b) \(74^2+24^2-48.74=24^2-2.24.74+74^2=\left(24-74\right)^2=\left(-50\right)^2=2500\)
Bài giải:
a) 342 + 662 + 68 . 66 = 342 + 2 . 34 . 66 + 662 = (34 + 66)2 = 1002 = 10000.
b) 742 + 242 – 48 . 74 = 742 - 2 . 74 . 24 + 242 = (74 - 24)2
=502 =2500
1) tính nhanh
a)342+662+68.66
b)742+242-48.74
a) 342+662+68.66=342+662+2.34.66
=(34+66)2=1002=10000
b)742+242-48.74=742+242-2.24.74
=(74-24)2=502=2500
tĩnh nhanh
a. 342+662+68.66
b. 742+242-48.74
\(\left(34+66\right)^2-2.34.66+68.66=100^2=10000\)
ý b tương tự nhé
tinh nhanh :
a) 342+662+68.66;
b) 742+242-48.74
a) 342+662+68.66 = 342+2.34.66+662=(34+66)2 = 1002 = 10000
b) 742+242-48.74 = 242 - 2.24.74+742 = (24 - 74)2 = (-50)2 = 2500
Tính nhanh:
a) 41^2+82.50+59^2
b) 89^2-18.89.9^2
c) (31,8)^2 - 31,8. 21,8+( 21,9)^2
d) 34^2 + 68.66+66^2
e)74^2+ 24^2- 48.74