Question

so that X= 3 and Y = 4 is not a solution of the following pair of linear equation 5 x -2y=7, x-2y=10​

Answer 1

Answer:

Step-by-step explanation:given x=3 y=4

In first case 5x-2y=7

By filling value of x and y

5(3)-2(4)=7

7=7 so it is solution of this equation

In second case x-2y=10

(3)-2(4)=10

3-8=10

-5=10,which is not possible therefore it os not solution of this equation

Thank you

Answer 2

Answer:

x=-3/20

y=-43/8

Step-by-step explanation:

rearrange the equation

5x=7+2y

x=(7+2y)/5

x=10+2y

then put then into simultaneous equations

(7+2y)/5=10+2y

bring the 5 over to the other side we dont want division  

7+2y=(10+2y)*5

times 5 by everything in the bracket

7+2y=50+10y

bring the +2y over to the other side and because its positive it becomes a negative

7=50+10y-2y, 7=50+8y

bring the 7 over same thing positive so will become negative

0=50-7+8y, 0=43+8y

now we want y on its own

-8y=43

y=-43/8 it now divide because times becomes divide vice versa

subsatue it in

5x-2*-43/8=10

x=-3/20