Answer:
Step-by-step explanation:
if the ratio is 8:11 then 40:x
Cross multiply
8 40
11 x
8x=440
And divide by 8
x=55. She has 55 books
Answer:
<u>There were 12 gold coins in the chest at the start.</u>
Step-by-step explanation:
1. Let's review the information given to us to answer the question correctly:
x = Number of gold coins in a chest
1/2x = Number of gold coins taken by the captain
1/4x = Number of gold coins taken by Sally
3 = Number of gold coins left
2. How many coins were in the chest at the start?
Let's write the following equation to solve for x:
1/2x + 1/4x + 3 = x
2x + x + 12 = 4x (Lowest Common Denominator is 4)
4x - 2x - x = 12 (Like terms)
x = 12
<u>There were 12 gold coins in the chest at the start.</u>
Answer:
D. Pythagorean
Step-by-step explanation:
Given the identity
cos²x - sin²x = 2 cos²x - 1.
To show that the identity is true, we need to show that the left hand side is equal to right hand side or vice versa.
Starting from the left hand side
cos²x - sin²x ... 1
According to Pythagoras theorem, we know that x²+y² = r² in a right angled triangle. Coverting this to polar form, we have:
x = rcostheta
y = rsintheta
Substituting into the Pythagoras firnuka we have
(rcostheta)²+(rsintheta)² = r²
r²cos²theta+r²sin²theta = r²
r²(cos²theta+sin²theta) = r²
(cos²theta+sin²theta) = 1
sin²theta = 1 - cos²theta
sin²x = 1-cos²x ... 2
Substituting equation 2 into 1 we have;
= cos²x-(1-cos²x)
= cos²x-1+cos²x
= 2cos²x-1 (RHS)
This shows that cos²x -sin²x = 2cos²x-1 with the aid of PYTHAGORAS THEOREM
Answer:A
Step-by-step explanation:
Answer:
y= 1/4 x +7
Step-by-step explanation:
The slope intercept form of a line is
y = mx + b where m is the slope and b is the y intercept
the slope is 1/4 and the y intercept is 7
y= 1/4 x +7
