5)
D
-10 + 7x
70°
E
12x + 10
А с
A) 12
C) 8
B) 10
D) 2

B) 10

Step-by-step explanation:

Exterior angle property: Exterior angle equals the sum of opposite interior angles.

12x + 10 = -10 + 7x +  70 {Subtract 10 from both sides}

12x        = -10 + 7x + 70 - 10        

       12x = -10 + 70 - 10 + 7x  {Combine like terms}

      12x  = 50 + 7x          {Subtract 7x from both sides}

12x - 7x = 50

       5x = 50 {Divide both sides by 5}

         x = 50/5

x = 10

f(x) = - 2/3x + 5; f(5/2)

substitute 5/2 in for x:

f(5/2) = -2/3(5/2) + 5

simplify the right side:

f(5/2) = -5/3 + 5

f(5/2) = 10/3

answer:

f(5/2) = 10/3

i hope this you!