Answer:
y = 4x + 5 and y = 4x - 5
Explanation:
(1) y = 4x + 5 and (2) y = 4x - 5
substitute (1) to (2):
4x + 5 = 4x - 5 subtract 4x from both sides
5 = -5 FALSE (no solution)
(1) y = 4x + 5 and (2) 2y = 8x + 10
substitute (1) to (2):
2(4x + 5) = 8x + 10 divide both sides by 2
4x + 5 = 4x + 5 subtract 4x from both sides
5 = 5 TRUE (infinitely many solutions)
(1) y = 4x + 5 and (2) y = x + 5
substitute (1) to (2):
4x + 5 = x + 5 subtract 5 from both sides
4x = x subtract x from both sides
3x = 0 divide both sides by 3
x = 0
Put it to (2):
y = 0 + 5 = 5
One solution (0, 5)
(1) y = 4x + 5 and (2) y = 8x + 10
substitute (1) to (2):
4x + 5 = 8x + 10 subtract 5 from both sides
4x = 8x + 5 subtract 8x from both sides
-4x = 5 divide both sides by (-4)
x = -1.25
Put it to (1):
y = 4(-1.25) + 5 = -5 + 5 = 0
One solution (-1.25, 0)