A, B, C and D are points on the circumference of a circle, centre O. ED is a tangent to the circle.

E

Angle ODB = 25°

А

Work out angle BAD.

You must give a reason for each stage

of your working.

250

D

B

С

Total marks: 4

PLEASE HELPPP

Angle at BAD = 115°

Step-by-step explanation:

Angle at ODB = 25°

Step 1: Joining point B to the centre of the circle gives an equilateral triangle

Angle at OBD = 25° (base angles of an equilateral triangle are equal)

Angle at BOD = 180° - (25° + 25°) = 130° (sum of angles of a triangle = 180°)

Reflex angle at BOD = 360° - 130° = 230° (sum of angles at a point = 360°)

Step 2: Joining point B to A and point D to A gives another triangle

Angle at BAD = ½ × 230° = 115° (angle at centre is twice the angle at any point on the circumference)

Therefore, angle at BAD = 115°

there are many solutions.

step-by-step explanation:

step 1: simplify both sides of the equation.

4x+6=4x^2+10x−4

step 2: subtract 4x^2+10x-4 from both sides.

4x+6−(4x^2+10x−4)=4x^2+10x−4−(4x^2+10x−4)

−4x^2−6x+10=0

step 3: factor left side of equation.

−2(2x+5)(x−1)=0

step 4: set factors equal to 0.

x=-5/2 or x=1