Sagot :
x= -1 and y=2
Proof:
-4x+5y=14 (equation 1)
7x+3y= -1 (equation 2)
3y= -7x -1
y= -7/3x -1/3 (equation 3)
(3) into (1)
-4x+5(-7/3x-1/3)=14
-4x-35/3x-5/3=14
-47/3x-5/3=14
-47/3x=47/3
x= (-47/3)/ (47/3)
x= -1
sub x= -1 into (3)
y= -7/3(-1)-1/3
y= 2
Proof:
-4x+5y=14 (equation 1)
7x+3y= -1 (equation 2)
3y= -7x -1
y= -7/3x -1/3 (equation 3)
(3) into (1)
-4x+5(-7/3x-1/3)=14
-4x-35/3x-5/3=14
-47/3x-5/3=14
-47/3x=47/3
x= (-47/3)/ (47/3)
x= -1
sub x= -1 into (3)
y= -7/3(-1)-1/3
y= 2
one way to solve is to try to cancel out some terms
we till try to cancel out the y terms
-4x+5y=14
7x+3y=-1
find lcm of 3 and 5 the lcm=15
-4x+5y=14
multily by 3
-12x+15y=42
7x+3y=-1
multiply both sides by -5
-35x-15y=5
add 2 equations together
-12x-35x+15x-15x=42+5
add like terms
-47x=47
divide both sides by 47
-x=1
multpiply by -1
x=-1
subsitute -1 for x in one quation
7x+3y=-1
x=-1
7(-1)+3y=-1
-7+3y=-1
add 7 to both sides
3y=6
divide both sides by 3
y=2
x=-1
y=2
we till try to cancel out the y terms
-4x+5y=14
7x+3y=-1
find lcm of 3 and 5 the lcm=15
-4x+5y=14
multily by 3
-12x+15y=42
7x+3y=-1
multiply both sides by -5
-35x-15y=5
add 2 equations together
-12x-35x+15x-15x=42+5
add like terms
-47x=47
divide both sides by 47
-x=1
multpiply by -1
x=-1
subsitute -1 for x in one quation
7x+3y=-1
x=-1
7(-1)+3y=-1
-7+3y=-1
add 7 to both sides
3y=6
divide both sides by 3
y=2
x=-1
y=2