Let f be the fraction invested at 10%. So (1-f) is the fraction at 7%. After one year the interest is
664 = 8200 f (.10) + 8200 (1-f) (.07) = 8200(.03)f + 8200(.07)
f = (664 - 8200(.07))/(8200(.03)) = .3659 = 36.59 %
Answer: 36.59%
Check:
8200(.3659)*.1 + 8200(1-.3659)*.07 = 664.01 good
When we see

has only 1 soulution
because its range is [0,π]
so only one solution exist at π/2
C im not completly sure but there you go i hope i helped
Answer: 30%
Step-by-step explanation:
It increased by 15 so it increased by 15/50=30/100=30%
I hope this helped!
(b)
The 50 degree angle and angle b are vertical angles, which means they are congruent.
The 50 degree angle and angle c are a linear pair, which means that they are supplementary/add up to 180 degrees.
Angles a and c are vertical angles, which means they are congruent.
a = 130
b = 50
c = 130
(c)
The 90 degree angle and angle b are vertical angles, which means they are congruent.
The 50 degree angle and angle c are vertical angles, which means they are congruent.
The 50 degree angle, 90 degree angle, and angle d all form a line, which means that they are supplementary and add up to 180.
Angle d and angle a are vertical angles, which means they are congruent.
a = 40
b = 90
c = 50
d = 40
(e)
The measure of a circle is 360 degrees. These three angles form a circle, so therefore if we add them all up, they will equal 360 degrees.
3a + 4a + 5a = 360
12a = 360
a = 30
(f)
The measure of a circle is 360 degrees. These four angles form a circle, so therefore if we add them all up, they will equal 360 degrees.
3a + 4a + 5a + 6a = 360
18a = 360
a = 20
Hope this helps!! :)