Question

Verificați egalitatile:a)
a)7/15-4/15-2/15=7/15-(4/15+2/15)
b) 8/15-(7/15-1/15)=8/15-7/15+1/15
c) 4 5/9-2 1/9=(4-2)+(5/9-1/9)=2 4/9​

Answer 1

Explicație pas cu pas:

$\mathbf{a) \frac{7}{15} - \frac{4}{15} - \frac{2}{15} = \frac{7}{15} - ( \frac{4}{15} + \frac{2}{15} ) }$

$\mathbf{ - \frac{4}{15} - \frac{2}{15} = - ( \frac{4}{15} + \frac{2}{15} )}$

$\mathbf{ - \frac{4}{15} - \frac{2}{15} = - \frac{2}{5} }$

$\mathbf{ - \frac{2}{5} = - \frac{2}{5} \: \: egalitate \: adevarata }$

$\mathbf{b) \frac{8}{15} - ( \frac{7}{15} - \frac{1}{15}) = \frac{8}{15} - \frac{7}{15} + \frac{1}{15} }$

$\mathbf{ - ( \frac{7}{15} - \frac{1}{15}) = - \frac{7}{15} + \frac{7}{15} }$

$\mathbf{ - \frac{2}{5} = - \frac{7}{15} + \frac{1}{15} }$

$- \frac{2}{5} = - \frac{6}{15}$

$\mathbf{ - \frac{2}{5} = - \frac{2}{5} \: \: egalitate \: adevarata}$

$\mathbf{c)4 \frac{5}{9} - 2 \frac{1}{9} = (4 - 2) + ( \frac{5}{9} - \frac{1}{9}) }$

$\mathbf{ \frac{36 + 5}{5} - \frac{18 + 1}{9} = 2 + \frac{4}{9} }$

$\mathbf{ \frac{41}{5} - \frac{19}{9} = \frac{22}{9} }$

$\mathbf{ \frac{274}{45} = \frac{22}{9} }$

$\mathbf{274 \times 9 = 22 \times 45}$

$\mathbf{2466 = 990 \: \: \: egalitate \: falsa}$

Bafta!