2x+3y=1;x+4y=−2
Steps:
Multiply the second equation by -2, then add the equations together.
(2x+3y=1)
−2(x+4y=−2)
Becomes:
2x+3y=1
−2x−8y=4
Add these equations to eliminate x:
−5y=5
Then solve−5y=5for y:
−5y−5=5−5(Divide both sides by -5)
y=−1
Now that we've found y let's plug it back in to solve for x.
Write down an original equation:
2x+3y=1
Substitute−1foryin2x+3y=1:
2x+(3)(−1)=1
2x−3=1(Simplify both sides of the equation)
2x−3+3=1+3(Add 3 to both sides)
2x=4
2x2=42(Divide both sides by 2)
x=2
Answer:
x=2 and y=−1
