Question

for questions 1-3, what is the solution of the system? use substitution. (will give medal and fan)
1. y=x+6
y=2x (1 point)
-(6,12)
-(-12,-6)
-(-6,-12)
-(2,4)
2. 3x+2y=7
-3x+11=y (1 point)
-(6,-3)
-(6,-7)
-{-4,19/2}
-(5,-4)
3. 2x-y=-7
4x-y=-4 (1 point )
-(-1.5,4)
-(1.5,10)
-(4,-1.5)
-(-1.5,-2)

Answer 1

1. y = x + 6
y = 2x
sub in 2x for y
2x = x + 6
2x - x = 6
x = 6
now sub 6 in for y in either of the above equations to find y
y = x + 6
y = 6 + 6
y = 12
SOLUTION : (6,12)

2. 3x + 2y = 7
-3x + 11 = y
sub in -3x + 11 for y in the 1st equation
3x + 2(-3x + 11) = 7 -- distribute through the parenthesis
3x - 6x + 22 = 7 -- subtract 22 from both sides
3x - 6x = 7 - 22 -- combine like terms
-3x = - 15 -- divide by -3
x = 5
sub in 5 for x in either equation to find y
-3x + 11 = y
-3(5) + 11 = y
-15 + 11 = y
-4 = y
SOLUTION : (5,-4)

3. 2x - y = -7 -->2x + 7 = y
4x - y = -4
now sub 2x + 7 in for y in the 2nd equation
4x - (2x + 7) = -4 -- distribute through the parenthesis
4x - 2x - 7 = -4 -- add 7 to both sides
4x - 2x = -4 + 7 -- combine like terms
2x = 3
x = 3/2 or 1 1/2 or 1.5
now sub 3/2 in for x in either of the equations
2x - y = -7
2(3/2) - y = -7
6/2 - y = -7
3 - y = -7 -- add y to each side
3 = y - 7 -- add 7 to both sides
3 + 7 = y
10 = y
SOLUTION : (1.5, 10)

Answer 2

Thank you so much!! youre a savior! <(^~^<)