Question

Solve the simultaneous equations

2
x
+
3
y
=
5
5
x
−
2
y
=
−
16

Answer 1

x = -2, y = 3

Explanation:

2x + 3y = 5

5x - 2y = -16

In order to find the value of a variable, we must eliminate the other variable by multiplying the equations to get the same coefficient.

We can multiply the first equation by 5 and the second one by 2 to get the same coefficient for x, the equations then become:

10x + 15y = 25

10x - 4y = -32

Now we can subtract:

19y = 57

y = 3

Since we know the value of y, we can substitute it into one of the original equations:

2x + 3(3) = 5

2x + 9 = 5

2x = -4

x = -2