Perimeter is 20 and the area is 25
Its not clearly given that whether EBF = 2x + 9 or 2x - 9.
I have written the solution for both.
If EBF = 2x + 9,
then ABF = 6x + 26 and ABE = 11x - 31.
Now, ABE = ABF + EBF
11x - 31 = (6x + 26) + (2x + 9)
= (6x + 2x) + (26 + 9)
= 8x + 35
11x - 8x = 35 + 31
3x = 66
x = 22
Therefore, ABF = 6x + 26 = 6(22) + 26 = 132 + 26 = 158°
If EBF = 2x - 9,
then ABF = 6x + 26 and ABE = 11x - 31.
Now, ABE = ABF + EBF
11x - 31 = (6x + 26) + (2x - 9)
= (6x + 2x) + (26 - 9)
= 8x + 17
11x - 8x = 17 + 31
3x = 48
x = 16
Therefore, ABF = 6x + 26 = 6(16) + 26 = 96 + 26 = 122°
45 Degrees on each side means it is equal, for an "equilateral" triangle.
First thing you should do is reduce coefficients.
1st equation has all multiples of '2'. Divide by 2
---> x +3y = -6
2nd equation has multiples of 5. Divide by 5.
---> x - y = 2
Now elimination part is easier.
Eliminate 'x' variable by subtracting 2nd equation from 1st.
x + 3y = -6
-(x - y = 2)
----------------------
4y = -8
Solve for 'y'
4y = -8
y = (-8)/4 = -2
Substitute value for 'y' back into 2nd equation:
x - (-2) = 2
x + 2 = 2
x = 0
Solution to system is:
x=0, y =-2