How many solutions does the system have? { y = -2x + 4 { 7y = -14x + 28 Choose 1 answer: A. Exactly one solution B. No solutions C. Infinitely many solutions
Mathematics · Middle School · Mon Jan 18 2021
Answered on
Solve equation [2] for the variable y
7y = 7x + 28
y = x + 4
Plug this in for variable y in equation [1]
-8x + 4•(x +4) = 24
-4x = 8
Solve equation [1] for the variable x
4x = - 8
x = - 2
By now we know this much :
x = -2
y = x+4
Use the x value to solve for y
y = (-2)+4 = 2
Solution :
{x,y} = {-2,2}
and this intersects at only one point so your answer is A