What's the measure of angle /_A?
I don't know if you can see it well enough but...

∠ A = 50°

Step-by-step explanation:

The angle at the centre COB is twice the angle at the circumference CDB

∠ COB = 2 × 65° = 130°

The angles ACO = ABO = 90° ( angle between radius and tangent )

The sum of the angles in quadrilateral ABOC = 360° thus

∠ A = 360° - (90 + 90 + 130)° = 360° - 310° = 50°

25.2

step-by-step explanation:

2+4x6-8/10= 25.2

d, x=8

step-by-step explanation:

simplifying

4x + -5 = 2x + 11

reorder the terms:

-5 + 4x = 2x + 11

reorder the terms:

-5 + 4x = 11 + 2x

solving

-5 + 4x = 11 + 2x

solving for variable 'x'.

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

add '-2x' to each side of the equation.

-5 + 4x + -2x = 11 + 2x + -2x

combine like terms: 4x + -2x = 2x

-5 + 2x = 11 + 2x + -2x

combine like terms: 2x + -2x = 0

-5 + 2x = 11 + 0

-5 + 2x = 11

add '5' to each side of the equation.

-5 + 5 + 2x = 11 + 5

combine like terms: -5 + 5 = 0

0 + 2x = 11 + 5

2x = 11 + 5

combine like terms: 11 + 5 = 16

2x = 16

divide each side by '2'.