Question

cine mă poate ajuta la mate​

Answer 1

Explicație pas cu pas:

a)

$\huge - \frac{2}{7} - ( - \frac{5}{7} ) = - \frac{2}{7} + \frac{5}{7} = \frac{ - 2 + 5}{7} = \frac{3}{7}$

b)

$\huge - \frac{4}{3} - (+ \frac{70}{3} ) = - \frac{4}{3} - \frac{70}{3} = \frac{ - 4 - 70}{3} = \frac{ - 74}{3} = - \frac{74}{3}$

c)

$\huge \frac{9}{4} -( - \frac{3}{4} ) = \frac{9}{4} + \frac{3}{4} = \frac{9 + 3}{4} = \frac{12}{4} = 3$

d)

$\huge + {}^{2)} \frac{1}{3} - ( + \frac{1}{6} ) = \frac{1 \times 2}{3 \times 2} - \frac{1}{6} = \frac{2}{6} - \frac{1}{6} = \frac{2 - 1}{6} = \frac{1}{6}$

e)

$\huge- \frac{2}{5} - ( - \frac{7}{10} ) = - {}^{2)} \frac{2}{5} + \frac{7}{10} = - \frac{2 \times 2}{5 \times 2} + \frac{7}{10} =- \frac{4}{10} + \frac{7}{10} = \frac{-4 + 7}{10} = \frac{3}{10}$

f)

$\huge \frac{5}{12} - (- \frac{1}{6} ) = \frac{5}{12} + {}^{2)} \frac{1}{6} = \frac{5}{12} + \frac{1 \times2 }{6 \times 2} = \frac{5}{12} + \frac{2}{12} = \frac{5 + 2}{12} = \frac{7}{12}$

g)

$\huge - \frac{1}{24} - ( + \frac{9}{8} ) = - \frac{1}{24} - {}^{3)} \frac{9}{8} = - \frac{1}{2} - \frac{9 \times 3}{8 \times 3} = - \frac{1}{24} - \frac{27}{24} = - \frac{1 + 27}{24} =- \frac{28}{24} {}^{(4} =- \frac{28 \div 4}{24 \div 4} =- \frac{7}{6}$

h)4,5-(4,5-3)=4,5-1,5=3

i)-7,7-(-2,8)-9=-7,7+2,8-9=-4,9-9=-13,9