63.0k views
4 votes
What is the solution to the system?

Line 1
x    y
–1 –2
1 2
Line 2
x    y
–2 10
4 1

( , )

1 Answer

6 votes
so we convert them to slope-intercept form which is y=mx+b where m=slope and b=y intercept

first line
(-1,-2)
(1,2)
slope=(y1-y2)/(x1-x2)
x1=-1
y1=-2
x2=1
y2=2
subsitute
(-2-2)/(-1-1)=-4/-2=4/2=2
slope=2
subsitute
y=2x+b
subsitute another point
(1,2)
x=1
y=2 is one solution
2=2(1)+b
2=2+b
subtract 2 from both sides
0=b
the equation is y=2x+0 or y=2x




other equation
(-2,10)
(4,1)
x1=-2
y1=10
x2=4
y2=1
subsitute
(10-1)/(-2-4)=9/-6=-3/2
slope=-3/2
y=-3/2x+b
subisute points that work
(-2,10)
x=-2
10=y is one solution
10=-3/2(-2)+b
10=6/2+b
10=3+b
subtract 3
7=b
y=-3/2x+7

we have y=-3/2x+7 and y=2x
subsitute
2x=y=-3/2x+7
2x=-3/2x+7
add 3/2x to both sides
2x+3/2x=7
2x=4/2x
4/2x+3/2x=7
7/2x=7
multiply both sides by 2/7
x=14/7
x=2
subisute for y
y=2x
y=2(2)
y=4


the point is (2,4)
User Jayesef
by
8.0k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories