Question

Bardzo Was proszę o rozwiązanie met. podstawiania ;]

1)

Jak najszybciej, proszę! :)

Answer 1

A)
4x + 8 = 1 - 5y
3y + 6 = 3 - 2x

4x + 8 = 1 - 5y
y = -1 - 2/3x

4x + 8 = 1 - 5(-1 - 2/3x)
y = -1 - 2/3x

4x = -7 + 5 + 10/3x
y = -1 - 2/3x

x - 5/6x = -1/2
y = -1 - 2/3x

1/6x = -1/2
y = -1 + 2

x = -3
y = 1

b)
2x + 2y - 3x + 3y = 4
4x + 4y - 7x + 7y = 4

-x + 5y = 4
-3x + 11y = 4

-x = 4 - 5y
12 - 15y + 11y = 4

x = 5y - 4
4y = 8

y = 2
x = 6

c)

1/2x - 1/3y = 1
1/4x - 2/3y = 8

6/12x - 4/12y = 1
3/12x - 8/12y = 8

6x - 4y = 12
3x - 8y = 96

3x = 6 + 2y
6 + 2y - 8y = 96

3x = 6 + 2y
-6y = 90

y = -15
3x = 6 - 30

y = -15
x = -8