How do you solve 3x + y = 33x+y=3, x - 4y = 1x−4y=1?
1 Answer
Mar 21, 2018
Explanation:
3x+y=3to(1)3x+y=3→(1)
x-4y=1to(2)x−4y=1→(2)
"from equation "(1)" we can express y in terms of x"from equation (1) we can express y in terms of x
rArry=3-3xto(3)⇒y=3−3x→(3)
color(blue)"Substitute "y=3-3x" into equation "(2)Substitute y=3−3x into equation (2)
x-4(3-3x)=1x−4(3−3x)=1
rArrx-12+12x=1⇒x−12+12x=1
rArr13x-12=1⇒13x−12=1
"add 12 to both sides"add 12 to both sides
13xcancel(-12)cancel(+12)=1+12
rArr13x=13rArrx=1
"Substitute "x=1" into equation "(3)
rArry=3-3=0
"solution is "(x,y)to(1,0)
