A = 4 / 7×31 + 6 / 7×41 +9 / 10 x41 + 7 / 10 x57
B = 7 / 19 x 31 + 5 / 19 x 43 + 3 / 23 x43 + 11 / 23 x 57
A = 4 / 7×31 + 6 / 7×41 +9 / 10 x41 + 7 / 10 x57 B = 7 / 19 x 31 + 5 / 19 x 43 + 3 / 23 x43 + 11 / 23 x 57
By Aubrey
By Aubrey
A = 4 / 7×31 + 6 / 7×41 +9 / 10 x41 + 7 / 10 x57
B = 7 / 19 x 31 + 5 / 19 x 43 + 3 / 23 x43 + 11 / 23 x 57
Đáp án:
Giải thích các bước giải:A=124/7+6/7*41+9/10*41+7/10*57
=124/7+6/7*41+9/10*41+7/10*57,
=124/7+246/7+9/10*41+7/10*57,
=124/7+246/7+369/10+7/10*57,
=124/7+246/7+369/10+399/10
=4538/35
b=7217/19+5/19*43+3/23*43+11/23*57
=217/19+215/19+3/23*43+11/23*57
=217/19+215/19+129/23+11/23*57
=217/19+215/19+129/23+627/23
=24300/437