Question

Tính nhanh

a) (45-63+18) x (1+2+3+4+5+6+7+8+9)

b) 60-61+62-63+64-65+66-67+68-69+70

Answer 1

a ) bằng 0.

b ) bằng 65.

Answer 2

a. (45-63+18) x (1+2+3+4+5+6+7+8+9)

= 0 x (1+2+3+4+5+6+7+8+9) = 0

b. 60-61+62-63+64-65+66-67+68-69+70

= 60 + (-61-69)+(62+68)+(-63-67)+(64+66)-65+70

= 60 + (-130)+130+(-130)+130-65-70

= 60 + (-130+130) + (-130+130)-65+70

= 60 - 65 + 70 = 65

Answer 3

(sai rồi)

Answer 4

a)(45-63+18)×(1+2+3+4+5+6+7+8+9) =0×(1+2+3+4+5+6+7+8+9) =0 b)60-61+62-63+64-65+66-67+68-69+70 =(60+70)+(-61-69)+(62+68)+(-63-67)+(64+66)-65 =130-130+130-130-65 =-65

Answer 5

(45-63+18)(45) =(^¿^)