1.
x - 2y = -19
5x + 2y = 1 /+
6x = -18 / 6
x = -3
-3 - 2y = -19
-2y = -16. / ÷(-2)
y = 8
2.
3x + 4y = 18
-2x + 4y = 8 / ×(-1)
3x + 4y = 18
2x - 4y = -8 /+
5x = 10 / ÷5
x = 2
3 × 2 + 4y = 18
6 + 4y = 18 / -6
4y = 12 / ÷4
y = 3
3.
2x + y = 3
-x + 3y = -12 / ×2
2x + y = 3
-2x + 6y = -24 /+
7y = -21 / ÷7
y = -3
2x - 3 = 3 / +3
2x = 6 / ÷2
x = 3
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