Answer:
-2y +2
Step-by-step explanation:
(x-y+1) - (x+y+-1)
Distribute the minus sign
x-y+1 -x-y+1
Combine like terms
-2y +2
<span><span>A) Sally’s statement is sometimes true. The equations students write to support their answers will vary. Sample pairs of equations that support the answer “sometimes true” are as follows:
Sample addition equation:–6.2 + 5.71 = –0.49Sample subtraction equation:–3.96 – 2.84 = –6.8
</span></span><span><span>B) You can always change the order of positive and negative decimals when adding and you’ll get the same answer. When you change the order of positive and negative decimals when subtracting, you will get opposite answers.
C) Sally’s statement is true for addition of three positive and negative decimals but not true for subtraction. The equations students write to support their answers will vary. Sample pairs of equations that support the answer that Sally’s statement is true for addition but not subtraction are as follows:
Sample addition equation:
–6.2 + 5.71 + (–3.96) = –4.45Sample subtraction equation:2.84 – (–3.96) – (–6.2) = 13</span></span>
You are supposed to already know the side lengths for these triangles in the Unit Circle. You need to take the time to memorize!
Triangles are "similar" if their angle measures are the same but their side lengths are different (they will be proportional, though). These triangles are 45°-45°-90° and 30°-60°-90°, respectively.
45°-45°-90°:
........./|
..1./....| [(√2)/2]
/____|
[(√2)/2]
30°-60°-90°:
..../|
1/..| [(√3)/2]
/__|
..½
note that the hypotenuse-length is always 1 when the triangle is inscribed in the Unit Circle. Multiplying the lengths of *every* side of a triangle by the same number creates a Similar Triangle.
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26) you know that one angle is 45°, and that this is a right triangle (because of the square in the corner). That means the other angle must be 45° and this is a well-known 45°-45°-90° triangle. You know the OPPOSITE side is 5 units long and the HYPOTENUSE is y units long. Therefore, for *this* triangle:
sin(45°) = OPP/HYP = 5/y
But from the Unit Circle, we also know the irreducible proportion for the SINE of a 45° angle is:
sin(45°) = OPP/HYP = [(√2)/2]/(1) = (√2)/2.
we can equate sin(45°) for similar triangles:
sin(45°) = sin(45°)
5/y = (√2)/2
multiply by reciprocals or identity-fractions until you get
y = 5√2
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27) you know that one angle is 30°, and that this is a right triangle (because of the square in the corner). That means the other angle must be 60° and this is a well-known 30°-60°-90° triangle. You know the OPPOSITE side is x units long, the ADJACENT side is 3√3 units long, and the HYPOTENUSE is y units long. You can solve for x and y by relating the TANGENT and COSINE proportions for *this* triangle...:
tan(30°) = OPP/ADJ = x/[(√3)/3]
cos(30°) = ADJ/HYP = [(√3)/3]/y
...with the TANGENT and COSINE proportions for the 30°-60°-90° triangle inscribed in the Unit Circle:
tan(30°) = {(½)/[(√3)/2]} = 1/√3 = [(√3)/3]
cos(30°) = {[(√3)/2]/(1)} = [(√3)/2]
Equate them:
tan(30°) = tan(30°)
x/[(√3)/3] = 1/√3
multiply by reciprocals or identity-fractions until you get
x = ⅓
cos(30°) = cos(30°)
[(√3)/3]/y = [(√3)/2]
multiply by reciprocals or identity-fractions until you get
y = 2/3
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I hope my answer has come to your help. Thank you for posting your question here in Brainly.
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Answer:
1st one:
Temperatures Cool With Increasing Latitude
As latitude increases, the sun shines more obliquely and provides less warming energy.
Step-by-step explanation:
3x/10-2 = x/5+2
+2 +2
3x/10 = x/5+4
x10 x10
3x = x(5 x 4)
-x -x
2x = 20
/2 /2
x=10