(c) Use a calculator to verify that Σ(x) = 64, Σ(x2) = 1118, Σ(y) = 628, Σ(y2) = 87,982, and Σ(x y) = 9,627.
1 answer:
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Answer:
<em>h=12, w=24, t=8</em>
Step-by-step explanation:
<u>System of Linear Equations </u>
We have 3 unknown variables and 3 conditions between them. They form a set of 3 equations with 3 variables.
We have the following data, being
w = price of a sweatshirt
t = price of a T-shirt
h = price of a pair of shorts
19.
The first condition states the price of a sweatshirt is twice the price of a pair of shorts. We can write it as
The second condition states the price of a T-shirt is $4 less than the price of a pair of shorts. We can write it as
The final condition states Brad purchased 3 sweatshirts, 2 pairs of shorts, and 5 T-shirts for $136, thus
This is the system of equations we need to solve for w,t,h
20.
To solve the system, we replace w in terms of h and t in terms of h. Those relations have been already written, so
Operating
Solving for h
The other two variables are
Answer:
-1
Step-by-step explanation:
We need to find the value of tan² 70° -sec² 70°.
We know that,
...(1)
We can write the given expression as :
tan² 70° -sec² 70° = -(-tan² 70° +sec² 70°)
=-(sec² 70°-tan² 70°)
Using identity (1)
=-(1)
= -1
Hence, the value of the given expression is -1.