7x +33 < 26 isolate the term with a variable by subtracting 33
7x < -7 divide by 7
x < -1
4.
b^-2-x^-2/b^-1+x^-1
b^-2/b^-1=b^-1
x^-2/x^-1=x^-1
As a result, the simplest form is:
b^-1-x^-1. Hope it help!
If tan0=-3/4 and 0 is in quadrant IV, cos20= (33/25, -17/25, 32/25, 7/25, 24/25?) and tan20= (24/7, -24/7, 7/25, -7/25, 13/7, -1
Oksana_A [137]
Answer:
- cos(2θ) = 7/25
- tan(2θ) = -24/7
Step-by-step explanation:
Sometimes, it is easiest to let a calculator do the work. (See below)
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The magnitude of the tangent is less than 1, so the reference angle will be less than 45°. Then double the angle will be less than 90°, so will remain in the 4th quadrant, where the cosine is positive and the tangent is negative.
You can also use the identities ...
cos(2θ) = (1 -tan(θ)²)/(1 +tan(θ)²)
cos(2θ) = (1 -(-3/4)²)/(1 +(-3/4)²) = ((16-9)/16)/((16+9)/16)
cos(2θ) = 7/25
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tan(2θ) = 2tan(θ)/(1 -tan(θ)²) = 2(-3/4)/((16-9/16) = (-6/4)(16/7)
tan(2θ) = -24/7
[ 2x + y = -9 ] x -3
[- 3x +11= y ] x 2
-6x -3y = 27
-6x + 22 = 2y
-6x +27 = 3y
-6x +22 = 2y
5 = y
-6x -3x5 = 27
-6x -15 = 27
-6x = 42
-x = 42/6
-x = 7
x = -7
answer
x = -7
y = 5