X² - 8x = -10
to have a complete square, we must have this format:
a² + 2ab + b²
a² = x²
2ab = -8x ⇒ 2(x)(-4)
b² = -4² = 16
x² - 8x + 16 = -10 + 16
x² - 8x + 16 = +6
(x-4)² - 6 = 0
Both sides must have an additional value of 16.
If you set you the equations such as 3c+5w=23 and 6c+2w=20 and then solve the first equation for c, you get c= (23-5w)/3 Taking that equation and substituting it for 'c' in the second equation (so the second equation becomes: 6((23-5w)/3)+2w=20 ) you get w=3.25 If you plug that back into your first equation (so it now becomes: 3c+5(3.25)=23 ) you get c=2.25 So the answer would be walnuts cost $3.25 per lb and choc. chips cost $2.25 per lb.
Option a:
sin A for the triangle is 
.
Solution:
The given triangle is a right triangle.
The adjacent side to angle A is AC.
The opposite side to angle A is BC.
Hypotenuse is AB.
AC = 8, BC = 6 and AB = 10.
Using trigonometric ratio formulas,
Divide both numerator and denominator by 2, we get
Hence sin A for the triangle is .
Option a is the correct answer.
