Answer:
solve by substitution method
Use o fato de que o determinante de qualquer matriz quadrada é o mesmo da sua transposta.
Answer:
68
Step-by-step explanation:
Let:
Number of girls invited = x
Number of boys = x +20
3/4 of boy showed up
2/3 of girls showed up
Exactly 19 did not show up
Therefore, we could say:
Fraction of boys that didn't show up = 1 - 3/4 = 1/4
Fraction of girls that didn't show up = 1 - 2/3 = 1/3
That is,
[1/4 *(x + 20)] + [1/3*x] = 19
[(x + 20) / 4] + x /3 = 19
(3(x + 20) + 4x) / 12 = 19
3x + 60 + 4x = 228
7x = 228 - 60
7x = 168
x = 168 / 7
x = 24
Number of girls, x = 24
Number of boys, x + 20 = 24 + 20 = 44
Total friends invited = (24 + 44) = 68
Answer:
can you zoom in on the screen please
Step-by-step explanation:
300
