Question

Tính nhanh:

a. 34^2 + 66^2 + 68 x 66

b. 74^2 + 24^2 - 48 x 74

Answer 1

a. 34^2 + 66^2 + 68 x 66

= 34 x 34 + 66 x 66 + 68 x 66

= 34 x 34 + 66 x (66 + 68)

= 34 x 34 + 66 x 134

= 34 x 34 + 66 x 34 + 66 x 100

= 34 x (34 + 66) + 66 x 100

= 34 x 100 + 66 x 100

= (34 + 66) x 100

= 100 x 100

= 10000

Answer 2

\(34^2+66^2+68.66\)

\(=34.34+66.66+68.66\)

\(=34.34+66.\left(68+66\right)\)

\(=34.34+66.134\)

\(=34.34+66.\left(100+34\right)\)

\(=34.34+66.100+66.34\)

\(=34.\left(66+34\right)+66.100\)

\(=34.100+66.100\)

\(=\left(34+66\right).100\)

\(=100^2\)

\(=10000\)