Question

Do no.7
eliminatiom method please

Answer 1

Answer:

Step-by-step explanation:

since the sides of an eqilateral triangle are equal.

6x+5y=2x+12y-2

or,4x=7y-2

or x=(7y-2)÷4.....(i)

Again

6x+5y=7x+3y+1

or,x=2y-1......(ii)

Comparing (i)and(ii)we get

2y-1=(7y-2)÷4

or,8y-4=7y-2

or,y=2

Therefore x=3

First side= 28 cm

Second side =28cm

Third side =28 cm

(D) is your answer

Answer 2

Answer:

Step-by-step explanation:

6x+5y=7x+3y+1

x-2y=-1............ (1)

2(x+6y-1) =7x+3y+1

5x-9y=-3............(2)

Multiple by 2 in (1)

5x-10y=-5 ......... (3)

5x-9y=-3............(2)

Subtract

-y=-2

y=2

Putting y=2 in (1)

x=-1+2×2

x=3

Side=6×3+5×2

=18+10

=28

(D) 28