=8.07× 10×8.7+8.07× 13

=8.07×87+8.07× 13

=8.07×(87+ 13)

=8.07× 100

=807

Using the laws of multiplication and distribution

17 ÷ 51+(1+2/0 of 565438+68) ×17.

= 17/5 1 + 1/68 × 17 + 2/5 1× 17

= 17/5 1 + 17/68 +34/5 1

= 17/5 1 +34/5 1 + 17/68

= 1 + 1/4

=5/4 (i.e. 1.25)

Multiplication and distribution combine similar items.

76× (65438 in 23+0-65438 in 53+0)+23× (65438 in 53+0+65438 in 76+0)-53× (65438 in 23+0-65438 in 76+0).

=76× 1/23 -76× 1/53 +23× 1/53 +23× 1/76 + -53× 1/23 +53× 1/76

In this step, multiply by the multiplication distribution law first, and then merge the similar items.

= 76/23 - 76/53 + 23/53 + 23/76 -53/23 + 53/76

= (76-53)/23 + (23-76)/53 + (23+53)/76

= 1 - 1 + 1

= 1

Ask if you don't understand ~