Y=1/4 x+7 y=1/2x+5 the why coordinate of the solution to the system shown is A.9 B.11 1/2 C. 19

Question

asked Nov 5, 2019 121k views

2 Answers

Tristanm · Answer 1 · 2019-11-11T14:30:25+0000

For this case we have a system of two equations with two unknowns, represented by x and y respectively.

$y=(1)/(4)x+7 (1)\\y=(1)/(2)x+5 (2)$

To solve we follow the steps below:

Step 1:

We multiply the second equation by -1

$y=(1)/(4)x+7\\-y=-(1)/(2)x-5$

Step 2:

We add both equations

$y-y=(1)/(4)x-(1)/(2)x+7-5\\0=-(1)/(4)x+2$

Step 3:

We clear x:

$(1)/(4)x=2\\x=4*2\\x=8$

Step 4:

We substitute "x" in any of the equations and clear "y":

$y=(1)/(2)x+5\\y=(1)/(2)(8)+5\\y=4+5\\y=9$

Thus, the solution of the system is given by:
(x, y) = (8,9)

Answer:

The y coordinate = 9

Option A