Question

11. Resolva os sistemas de equações pelo metodo que prefirir

Answer 1

8.

$p \: = \frac{9000t + 6000}{t - 1} \\ \\ p = \frac{9000 \times 13 + 6000}{13 - 1} \\ \\ p = \frac{123000}{12} = 10 \: 250$

Alternativa B.

11.

a)

x - y = 9
x = 9 + y

[ x + 3 ] / y = -5
[ 9 + y + 3] / y = -5
12 + y = -5y
y + 5y = -12
6y = -12
y = -12/6
y = -2

x = 9 + y
x = 9 + (-2)
x = 9 -2
x = 7

b)

y - x = 3
y = 3 + x

2y/x = 5/2
2 × 2y = 5 × x
4y = 5x
4(3 + x) = 5x
12 + 4x = 5x
5x + 4x = 13
9x = 13
x = 13/9

y = 3 + x
y = 3 + 13/9
y = [27 + 13] /9
y = 40/9