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Exercises: systems with two variables

Test your knowledge! Which method is useful to solve the following systems of equations?

$I 3 x + 6 y = 2$
$II 4 x + 2 = y$
- substitution method
- equating coefficients
- addition method
For this task you need the following basic knowledge: System of linear equations
The equation $II$ is already solved for $y$ . Therefore, the substitution method is advisable.
The other two methods also get you to the goal, but they require further transformation steps.
$I s = 4 t - 7$
$II s = - 2 + 3 t$
- substitution method
- equating coefficients
- addition method
For this task you need the following basic knowledge: System of linear equations
All three methods can be applied directly and are useful for this reason.
$I 2 a - 2 b = 3$
$II 5 a + 2 b = 6$
- substitution method
- equating coefficients
- addition method
For this task you need the following basic knowledge: System of linear equations
Equation $I$ contains $- 2 b$ , equation $II$ contains $2 b$ . So the $b$ will drop out when adding both lines, which makes the addition method suitable.
With the other two procedures, you have to take further transformation steps, before one can apply them.

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