It's the first one you can just add or multiply the expressions to get the answer
12 2 +16 2 = D2
D2= 144+256
D2= 400
D2= 400
Well since the triangle is split into 2 triangles and they both are the same size so BD on the bottom is 15 which means naturally BC must be 30. Five I'm not sure about
The value of A is 9. This is because 40-13= 27
3x?=27 3x9=27
2(5x-15) + 2(2x+7) =0
10x-30+4x+14 = 0
14x = 16
x = 8/7
