Question

Câu 14: Thực hiện phép tính:

a) $5,3 . 4,7+(-1,7) . 5,3-5,9$;

b) $\dfrac{2}{3}+\dfrac{-1}{3}+\dfrac{7}{15}$.

Answer 1

\(a.5,3.4,7+\left(-17\right).5,3-5,9\)

\(=5,3.\left[4,7+\left(-17\right)\right]-5,9\)

\(=5,3.\left(-12,3\right)-5,9\)

\(=-65,19-5,9=-71,09\)

\(b.\dfrac{2}{3}+\dfrac{-1}{3}+\dfrac{7}{15}=\dfrac{10}{15}+\dfrac{-5}{15}+\dfrac{7}{15}=\dfrac{12}{15}=\dfrac{4}{5}\)

Answer 2

a)5,3.4,7+(-1,7).5,3-5,9

=5,3.4,7+1,7.5,3-5,9

=5,3.(4,7+1,7-5,9)

=5,3.0,5

=2,65

b)2/3+-1/3+7/15

=10/15+-5/15+7/15

=5/15+7/15

=12/15

=4/5

Answer 3

a) 5,3 . 4,7 + (- 1,7) . 5,3 - 5,9

= 24,91 + (- 9,01) - 5,9

=15,9 - 5,9

=10

b) \(\dfrac{2}{3}\)+\(\dfrac{-1}{3}\)+ \(\dfrac{7}{15}\)

= \(\dfrac{10}{15}\)+\(\dfrac{-5}{15}\)+\(\dfrac{7}{15}\)

=\(\dfrac{15}{15}\)= 1

Answer 4

a)5,3.4,7+(-1,7).5,3-5,9

=24,91+(-9,01)-5,9

=15,9-5,9=10

b)2/3+(-1)/3+7/15

=1/3+7/15=4/5

Answer 5

a;5,3.4,7+(-1,7).5,3-5,9

=5,3.3-5,9

=15,9 - 5,9=10

Answer 6

a) $5,3.4,7+(-1,7).5,3-5,9$

$=5,3.(4,7-1,7)-5,9$

$=5,3.3-5,9$

$=15,9-5,9=10$

b) 23+−13+71532​+3−1​+157​

=2+(−1)3+715=32+(−1)​+157​

=5+715=1215=45=155+7​=1512​=54​.

Answer 7

a) $5,3.4,7+(-1,7).5,3-5,9$

$=5,3.(4,7-1,7)-5,9$

$=5,3.3-5,9$

$=15,9-5,9=10$

b)\(\dfrac{2}{3}+\dfrac{-1}{3}+\dfrac{7}{15}\)

=\(\dfrac{1}{3}\)+\(\dfrac{7}{15}\)

=\(\dfrac{5}{15}+\dfrac{7}{15}\)

=\(\dfrac{12}{15}\)=\(\dfrac{4}{5}\)

Answer 8

a) $5,3.4,7+(-1,7).5,3-5,9$

$=5,3.(4,7-1,7)-5,9$

$=5,3.3-5,9$

$=15,9-5,9=10$

b)\(\dfrac{2}{3}+\dfrac{-1}{3}+\dfrac{7}{15}\)

=\(\dfrac{1}{3}\)+\(\dfrac{7}{15}\)

=\(\dfrac{5}{15}+\dfrac{7}{15}\)

=\(\dfrac{12}{15}\)=\(\dfrac{4}{5}\)

Answer 9

chữ số là \(\infty\)

Answer 10

a) 10.

b) 4/5.

Answer 11

a) 5,3 . 4,7 + (-1,7) . 5,3 - 5,9

= 5,3 . (4,7 - 1,7) - 5,9

= 5,3 . 3 - 5,9

= 15,9 - 5,9

= 10

b) 2/3 + (-1/3) + 7/15

= 2/3 - 1/3 + 7/15

= 1/3 + 7/15

= 5/15 + 7/15

= 12/15

= 4/5