7+5x6+7=
Tính nhanh:
7/2x3+7/3x4+7/4x5+7/5x6
\(\dfrac{7}{2\times3}+\dfrac{7}{3\times4}+\dfrac{7}{4\times5}+\dfrac{7}{5\times6}\)
= 7 x ( \(\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{6}\) )
= 7 x \(\left(\dfrac{1}{2}-\dfrac{1}{6}\right)\)
= 7 x \(\dfrac{1}{3}=\dfrac{7}{3}\)
B=(-3x7^4+7^3)/(7^5x6-7^3x2)
tính thuận tiện nhất 4/7x3/7+4/5x6/7-4/5x7/14
`4/7xx3/7+4/5xx6/7-4/5xx7/14`
`=4/7xx3/7+4/5xx(6/7-7/14)`
`=4/7xx3/7+4/5xx5/14`
`=12/49+2/7`
`=26/49`
=4/7x3/7+4/5x(6/7-7/14)
=4/7x3/7+4/5x5/14
=12/49+2/7
=26/49
5-4/2x3 + 6-5/3x4 8-7/4x5+ 9-8/5x6
bài 1 tính nhanh
a 6/5x1/7+3/5x6/7 = ?
b 6/7x 3 2/7 x3
a, 24/35
b, 13/7
k cho mih
Hệ số cao nhất của đa thức 5 x 6 + 6 x 5 + x 4 - 3 x 2 + 7 là:
A. 6
B. 7
C. 4
D. 5
Tính bằng cách thuận tiện nhất :3/5x6/7+3/5x16/14-3/5
3/5x6/7+3/5x16/14-3/5x1
=3/5x(6/7+16/14-1)
=3/5x1
=3/5
7-4-2+5x3+5x6=?
Ib không? facebook.com/chi.cano.526
7-4-2+5x3+5x6
=3-2+5x(3+6)
=1+5x9
=1+45
=46
7 - 4 - 2 + 5 x 3 + 5 x 6
=3 - 2 + 5 x ( 3 + 6 )
=1 + 5 x 9
=1 + 45
=46
tinhs giá trị biểu thức
1/5x6 + 7/6 - 6/5 =
1/5 x 6 +7/6-6/5
=1/30+7/6-6/5
=1/30+35/30-36/30
=0/30
=0
1/5x6 + 7/6 - 6/5 = 1/30 + 7/6 - 6/5
= 1/30 + 35/30 - 36/30
= 36/30 - 36/30
=0/30 = 0
\(\frac{1}{5}\)x 6 + \(\frac{7}{6}\)- \(\frac{6}{5}\)
= \(\frac{6}{5}\) + \(\frac{7}{6}\) - \(\frac{6}{5}\)
= \(\frac{13}{5}\) - \(\frac{6}{5}\)
= \(\frac{7}{5}\)