The diagram shows an isosceles triangle. All the measurements are in cm.
3x – 5
19 – X
2x
Work out the perimeter of the triangle.​

-3.5

Step-by-step explanation:

3x + -5 + 19 + -1x + 2x = 0

Reorder the terms:

-5 + 19 + 3x + -1x + 2x = 0

Combine like terms: -5 + 19 = 14

14 + 3x + -1x + 2x = 0

Combine like terms: 3x + -1x = 2x

14 + 2x + 2x = 0

Combine like terms: 2x + 2x = 4x

14 + 4x = 0

Solving

14 + 4x = 0

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '-14' to each side of the equation.

14 + -14 + 4x = 0 + -14

Combine like terms: 14 + -14 = 0

0 + 4x = 0 + -14

4x = 0 + -14

Combine like terms: 0 + -14 = -14

4x = -14

Divide each side by '4'.

x = -3.5

Simplifying

x = -3.5

I hope i helped, thanks UvU

starting with:    

5 + x - 12 = 2x - 7   

5 + x - 12 - x = 2x - 7 - x (subtract x from both sides)   

5 - 12 = x - 7 (combine and cancel x's from both sides)   

5 - 12 + 7 = x - 7 + 7 (add 7 to both sides)   

0 = x (add numbers together on both sides)       

so in order for the equation to be true, x must be 0.   

trying x = -0.5   

5 + x - 12 = 2x - 7 (original equation)   

5 + -0.5 - 12 = 2(-0.5) - 7 (plug in value of x)   

5 + -0.5 - 12 = -1 - 7 (did multiplication)   

-7.5 = -8 (did addition on both sides)       

since -7.5 is obviously not equal to -8, the value of -0.5 for x is wrong.   

trying x = 0   

5 + x - 12 = 2x - 7 (original equation)   

5 + 0 - 12 = 2(0) - 7 (plug in value of x)   

5 + 0 - 12 = 0 - 7 (did multiplication)   

-7 = -7 (did addition on both sides)       

since -7 equals -7, that demonstrates that the value of 0 for x is correct.   

trying x = 1   

5 + x - 12 = 2x - 7 (original equation)   

5 + 1 - 12 = 2(1) - 7 (plug in value of x)   

5 + 1 - 12 = 2 - 7 (did multiplication)   

-6 = -5 (did addition on both sides)       

since -6 is obviously not equal to -5, the value of 1 for x is wrong.

my guess would be b and d, but i didn’t actually get out the pen and paper. lol