Question

[Phuong Vu]

Tính 

A:58×72+63×81-58×52--63×61

B:87×96-27×13+13×17-87×86

C:53×39+87×39-53×31-47-21

Tìm x :

X:(1800+600):30] :560 :(315:35)

Các bạn giai hộ mình 2 bài trên nhé

☺

Answer 1

[nguyenngocnhuhuynh]

X=(1800+600):30):560:(315:35)

X=(2400:30):560:9

X=80:560:9

X=80x1/560x1/9

X=1/7x1/9

X=1/63

Answer 2

[nguyenngocnhuhuynh]

A=58x72+63x81-58x52-63x61

  = (58x72-58x52)+(63x81-63x61)

  = 58(72-52)+63(81-61)

  = 58x20+63x20

  = 1160+1260

  = 2420