Answer:
(-5, 2)
Explanation:
2x + 3y = -4
x + 9y = 13
We can solve this by substituting or using elimination.
Substituting:
2x + 3y = -4
-2x = -2x Subtract 2 from both sides.
3y = -2x - 4
3 = 3 Divide both sides by 3.
y = -2/3x - 4/3
x + 9(-2/3x - 4/3) = 13 Replace the y with -2/3x - 4/3.
x - 6x - 12 = 13 use the distributive property.
-5x - 12 = 13
+12 = + 12 Add 12 to both sides.
-5x = 25
-5 = -5 Divide both sides by -5.
x = -5
Now that we know what x is, we substitute -5 for the variable x in any of the two equations.
x + 9y = 13
-5 + 9y = 13 Replaced x with -5
+5 = +5 Add 5 to both sides.
9y = 18
Divide both sides by 9 to get:
y = 2
The other way to solve:
Elimination:
2x + 3y = -4
x + 9y = 13
Make the variable y cancel out.
-3(2x + 3y = -4) use the distributive property.
-6x - 9y = 12
-6x - 9y = 12
x + 9y = 13
Add the equation.
-5x = 25
Divide both sides by -5.
x = -5
Plug in -5 for x.
2(-5) + 3y = -4
-10 + 3y = -4
+10 = +10 Add 10 to both sides.
3y = 6
Divide both sides by 3:
y = 2
We get the same answer in both strategies, you could use either one.