7. 2x+4y=16 and y=x-8

Question

Please show work, on a graph, need help badly

Answer 1

2x+4y =16

divide by 2

x +2y = 8

2nd equation

y=x-8

or

x-y =8

subtract last equation from x+2y=8

to get 3y=0 or y=0

x=8

solution is (8,0)

check the answer plug x=8, y=0 into each equation

or solve it graphically, graph each line

2x+4y=16

solve for y

y=-2x/4 +16/4 =-x/2 +4 is a line with slope -1/2 and y intercept 4 (0,4)

downward sloping line, x intercept = (8,0)

y=x-8 is a line with slope = 1 and y intercept =-8 = (0,-8)

upward sloping line, x intercept = (8,0)

since they both have the same x intercept, that's the point of intersection

or

carefully graph them and see where they intersect

even a rough sketch will narrow it down to the likely solution

use some graph paper

x-8= -x/2 +4

3x/2 = 12

x = 12(2/3) = 8

x=8

y=x-8 = 8-8=0

y=0