Here you have a system of 2 equations and 2 unknowns. An easy way to solve this type is to isolate one of the variables.
12a + 2b = 8
2b = 8 - 12a
b =

b = 4 - 6a
Now plug 4 - 6a into equation 1 to solve for a.
a + 5(4 - 6a) = 19
a + 20 - 30a = 19
-29a = -1
a = 1/29 (answer)
Now plug a into the equation for b
b= 4 - 6(1/29)
b= 110/29 (answer)
Answer:
{- 11, - 1 }
Step-by-step explanation:
Since the coefficient of the x² term is 1 , to complete the square
add (half the coefficient of the x-term )² to both sides
x² + 2(6)x + 36 = - 11 + 36 ← complete the square on the left side
(x + 6)² = 25 ( take the square root of both sides
= ± 
x + 6 = ± 5 ( subtract 6 from both sides )
x = - 6 ± 5
x = - 6 + 5 = - 1 or x = - 6 - 5 = - 11
Answer:
A. Measure of angle A + measure of angle B
Step-by-step explanation:
Because angle 4 is an exterior angle of given triangle which will be equal to the Measure of angle 2 + measure of angle 3