Question

1, Tính giá trị biểu thức

P= 1.2.3.4+2.3.4.5+3.4.5.6+4.5.6.7+...+97.98.99.100

Answer 1

5P=(5-0).1.2.3.4+(6-1).2.3.4.5+...+(101-96).97.98.99.100

5P=1.2.3.4.5-0+2.3.4.5.6-1.2.3.4.5+....+97.98.99.100.101-96.97.98.99.100

5P=97.98.99.100.101

5P=9505049400

S=1901009880

Answer 2

P = 1.2.3.4 + 2.3.4.5 + 3.4.5.6 + 4.5.6.7 + .. + 97.98.99.100

4P = ( 1.2.3 + 2.3.4 + 3.4.5 + 4.5.6 + .. + 98.99.100) 4

4P = 1.2.3.(4-0) + 2.3.4(5-1) + 3.4.5(6-2) + 4.5.6(7-3) + 98.99.100(101-97)

4P = 1.2.3.4 + 2.3.4.5 - 1.2.3.4 + 3.4.5.6 - 2.3.4.5 + 4.5.6.7 - 3.4.5.6 + .. 98.99.100.101 - 97.98.99.100

4P = 98.99.100.101

4P= 98.99.100.101/4

Nếu thấy đúng thì tích mk nha