Step-by-step explanation:
a. that's the best answer that suits the question per day you multiply by 22
Answer:
Given the system of equation:
......[1]
......[2]
we can rewrite equation [2] as;
......[3]
Substitute equation [3] into [1] to eliminate x, and solve for y;

Using distributive property: 

Combine like terms;
16 - 8y = -4
Add 4 to both sides we have;
20 - 8y = 0
Add 8y to both sides we have;
20 = 8y
Divide 8 to both sides we have;

Substitute the y-value in [3] we have;

x = 8 - 5 = 3
Therefore, the expression should be substituted into the first equation is,
and also the value of x = 3 and y = 2.5
Answer:
Step-by-step explanation: when you take 521 and divide it by 4 you get 130.25, which is about 130, making you choose answer choice B. (lol i like your profile picture too!!)
Answer:
Replace all occurrences of y with 2x−1 in each equation.
0=0
y=2x−1
Remove any equations from the system that are always true.
y=2x−1
Step-by-step explanation:
Answer:
-4sinθcosθ
Step-by-step explanation:
Note:
1. (a + b)^2 = a^2 + 2ab + b^2
2. (a - b)^2 = a^2 - 2ab + b^2
3. sin^2θ + cos^2θ = 1
(sinθ -cosθ)^2 - (sinθ + cosθ)^2
= sin^2θ - 2sinθcosθ + cos^2θ - (sin^2θ + 2sinθcosθ + cos^2θ)
= sin^2θ + cos^2θ - 2sinθcosθ - (sin^2θ + cos^2θ + 2sinθcosθ)
= 1 - 2sinθcosθ - (1 + 2sinθcosθ)
= 1- 2sinθcosθ -1 - 2sinθcosθ
= - 2sinθcosθ - 2sinθcosθ
= -4sinθcosθ