Question

tính nhanh

a, 58 x 42 + 32 x 8 + 5x16

Answer 1

a, 58 x 42 + 32 x 8 + 5 x 16

=  58 x 42 + 16 x 2 x 8 + 5 x 16

=  58 x 42 + 16 x 16 + 5 x 16

=  58 x 42 + 16 x ( 16 + 5 )

=  58 x 42 + 16 x 21

=  58 x 42 + 8 x 42

= 42 x ( 58 + 8 )

= 42 x 66

= 2772

Answer 2

a) ( 2 x 2 ) x 21x29 + 4 x( 8 x 8 )+ (5 x 4) x 4

= 4 x 609 + 4 x 64+20x4

=4x(609+64+20)

=4x693

=2772