Question

resuelve las siguientes operaciones mental mente:
3/8+ 1/4= 3/9+1/3=

1.5+3.2= 10-2.5=

5.4+2.7= 3.9+1.1=


:þ​

Answer 1

$\frac{3}{8} + \frac{1}{4} = \frac{3}{8} + \frac{2}{8} = \frac{3 + 2}{8} = \frac{5}{8}$

$\frac{3}{9} + \frac{1}{3} = \frac{3}{9} + \frac{3}{9} = \frac{3 +3 }{9} = \frac{6}{9} = \frac{2}{3}$

$1 \times 5 + 3 \times 2 = 5 + 6 = 11$

$10 - 2 \times 5 = 10 -1 0 = 0$

$5 \times 4 + 2 \times 7 = 20 + 14 = 34$

$3 \times 9 + 1 \times 1 = 27 + 1 = 28$