Question

. Tính nhanh: a) (45×105-225)-(210+42×95) b) (47×105-235)-(168+42×96) Giúp với ạ. E đang cần gấp.

Answer 1

a) \(\left(45x105-225\right)-\left(210+42x95\right)\)

\(=45x\left(100+5\right)-225-210+42x\left(100-5\right)\)

\(=4500+45x5-225-210+4200-42x5\)

\(=4500+4200+45x5-42x5-225-210\)

\(=8700+5x\left(45-42\right)-435\)

\(=8700+15-435=8280\)

Answer 2

a: =45*105-225-210-42*95

=45*(105-5)-42(95+5)

=100*3

=300

b: =47(105-5)-42(96+4)

=47*100-42*100

=5*100

=500

Answer 3

b) \(\left(47x105-235\right)-\left(168+42x96\right)\)

\(=47x\left(100+5\right)-235-168-42x\left(100-4\right)\)

\(=4700+235-235-168-4200-168\)

\(=4700-4200+235-235-168-168\)

\(=500\)