Answer:
x = -3
y = 7
Step-by-step explanation:
y = -2x + 1
7 = -2x + 1
<u>-1 -1 </u>
6 = -2x
divide by -2
x = -3
Answer:
25% of 30% of 400 = 30
33% decrease in value
Step-by-step explanation:
You can either get 30% of 400 first then 25% of 400 or you can get the total percentage of 400.
Method 1:
30% of 400 = 0.3 of 400 = 0.3 * 400 = 120
25% of 120 = .25 of 120 = .25 * 120 = 30
Method 2:
30% of 25% = 0.3 * 0.25 = 0.075 = 7.5% of 400
7.5% of 400 = 0.075 of 400 = 0.075 * 400 = 30
5.) To find the percentage of the new price, you can build the equation below.




The percentage decrease in price is then 100% of the original price - 66.667% of the original price = 100% - 66.67% = 33.33% = 33% decrease.
Answer:
He's correct.
Step-by-step explanation:
As long as there is no change in sign of the variables.
Answer:

Step-by-step explanation:
we know that

Remember the identity

step 1
Find the value of 
we have that
The angle alpha lie on the III Quadrant
so
The values of sine and cosine are negative

Find the value of sine

substitute




step 2
Find the value of 
we have that
The angle beta lie on the IV Quadrant
so
The value of the cosine is positive and the value of the sine is negative

Find the value of cosine

substitute




step 3
Find cos (α + β)

we have




substitute


