Look at the pic. thanks

{-7/2, 7/2}

Step-by-step explanation: To solve this polynomial equation,

we first need to set it equal to 0 by subtracting 68 from both sides.

That leaves us with 4a² - 49 = 0.

Notice that the left side represents the difference of 2 squares.

Since 4 factors as 2 · 2 and a² factors as a · a, 4a² factors as 2a · 2a

so we use those factors as the first term in each binomial.

Since 49 is also a perfect square, 7 · 7,

we use a 7 as the second term in each binomial.

So we have (2a + 7)(2a - 7) = 0.

This means that either 2a + 7 = 0 or 2a - 7 = 0.

Solving each equation from here, our solution set is {-7/2, 7/2}.

hope it you

step-by-step explanation:

sin(7pi/6 - pi/3)  

= sin(7pi/6 - 2pi/6)  

= sin(5pi/6)  

= sin(pi - pi/6)  

= sin(pi/6)  

= 1/2  

sin 7pi/6 - sin pi/3  

= sin (pi + pi/6) - sin pi/3  

= -sin pi/6 - sin pi/3  

= -1/2 - sqrt(3)/2  

= -(1+sqrt(3))2