Respuesta :

eloiseoleary22
Answer:20
5x add 3x is 8x 12 + 8 is 20 so 8x + 20 = 180 because it’s a straight line so 180-20 is 160 then divide 160 by 8 to work out 1 x rather than 8 x which is 20
josshyaby

Answer:

Step-by-step explanation:

This is an isosceles triangle so the two down angles are equal

(5x+12) + (3x+8) = 180° (angle on a straight line is equal 180°)

Open brackets

5x+12 + 3x+8 = 180

8x + 20 = 180

Collecting like terms

8x = 180 - 20

8x = 160

Dividing by 8

x = 160/8

x = 20°