Solve the system graphically
3 x + 4y =2 and 5x-y=11
Answers
Answer:
3x + 4y=2 }*5
5x-y=11}*3
15x+20y=10
15x-3y=33 } sign change (+ to -)
—————-
23y= -23
y=-1
y value put in (1) eq..
3x+4(-1)=2
3x-4=2
3x=2+4
3x=6
x=2
Answer: ans is simultaneously
3x+4y=2 .........(1) ×5
5x-y=11 ..........(2) ×3
multiplying equ. 1 with 5 and equ.2 with 3
we got ,
15x+20y=10
15x-3y=33
- + = - ( sign will be changed since we are going to substract )
23y = - 23
or y = -23/23
therefore, y = - 1
putting the value of y in equ.1
3x+4y=2
3x+4(-1)=2
3x+ -4 =2
3x=2+4
3x=6
x= 6/3
x= 2
therefore x= 2 and y = - 1
in graph the point of intersection is = ( - 1 , 2 )
OR ans is graphically
3x+4y=2..........(1)
5x-y=11.............(2)
from equation 1.
3x+4y=2
or 3x=2-4y
x= 2-4y/3 rough work
x= 2 , 2 , -4 y=0
y= -1 , -2 ,6 x=2-4y/3
=2-4(0)/3
=2/3
answer
should not be
in fraction.
y=-1
x= 2-4y/3
=2-4(-1)/3
=2 ans
like this we done in rough work we have to find three ans. both for equation (1)and(2).
from equation (2)
5x-y=11
5x=11+y
x= 11+y/5
x=2 , 3 , 1
y= -1 , 4 ,-6
in both equation 1and2
(2,-1) is common so it is the point of intersection in graph.