All categories

2 years ago

Please help me its do tomorrow

Mathematics

1 answer:

PolarNik [594]2 years ago

3 0

2x+3 + 3x-4 + 2x+3 + 3x-4 = 78
10x -2 = 78
10x = 80
x=8

deck is 2(8)+3 by 3(8)-4, or 19 by 20

You might be interested in

MATH HELP PLZ!!!

RoseWind [281]

Answer:

a) $tan (157.5) = \frac{1-cos 315}{sin315}$

$sin (165) =\sqrt{ \frac{1-cos (330) }{2}}$

$sin^{2} (157.5) = \frac{1-cos (315) }{2}$

cos 330° = 1- 2 sin² (165°)

Step-by-step explanation:

Step(i):-

By using trigonometry formulas

cos2∝ = 2 cos² ∝-1

cos∝ = 2 cos² ∝/2 -1

1+ cos∝ = 2 cos² ∝/2

$cos^{2} (\frac{\alpha }{2}) = \frac{1+cos\alpha }{2}$

cos2∝ = 1- 2 sin² ∝

cos∝ = 1- 2 sin² ∝/2

$sin^{2} (\frac{\alpha }{2}) = \frac{1-cos\alpha }{2}$

Step(i):-

Given

$tan\alpha = \frac{sin\alpha }{cos\alpha }$

we know that trigonometry formulas

$sin\alpha = 2sin(\frac{\alpha }{2} )cos(\frac{\alpha }{2} )$

1- cos∝ = 2 sin² ∝/2

Given

$tan(\frac{\alpha }{2} ) = \frac{sin(\frac{\alpha }{2} )}{cos(\frac{\alpha }{2}) }$

put ∝ = 315

$tan(\frac{315}{2} ) = \frac{sin(\frac{315 }{2} )}{cos(\frac{315 }{2}) }$

multiply with ' 2 sin (∝/2) both numerator and denominator

$tan (\frac{315}{2} )= \frac{2sin^{2}(\frac{315)}{2} }{2sin(\frac{315}{2} cos(\frac{315}{2}) }$

Apply formulas

$sin\alpha = 2sin(\frac{\alpha }{2} )cos(\frac{\alpha }{2} )$

1- cos∝ = 2 sin² ∝/2

now we get

$tan (157.5) = \frac{1-cos 315}{sin315}$

$sin^{2} (\frac{\alpha }{2}) = \frac{1-cos\alpha }{2}$

put ∝ = 330° above formula

$sin^{2} (\frac{330 }{2}) = \frac{1-cos (330) }{2}$

$sin^{2} (165) = \frac{1-cos (330) }{2}$

$sin (165) =\sqrt{ \frac{1-cos (330) }{2}}$

c )

$sin^{2} (\frac{\alpha }{2}) = \frac{1-cos\alpha }{2}$

put ∝ = 315° above formula

$sin^{2} (\frac{315 }{2}) = \frac{1-cos (315) }{2}$

$sin^{2} (157.5) = \frac{1-cos (315) }{2}$

cos∝ = 1- 2 sin² ∝/2

put ∝ = 330°

$cos 330 = 1 - 2sin^{2} (\frac{330}{2} )$

cos 330° = 1- 2 sin² (165°)

3 0

2 years ago

Help me please I have 10 minutes to do this

Olin [163]

Answer:

Distributive

Step-by-step explanation:

The 4y is distributed to the terms in parentheses.

7 0

2 years ago

4x − 1 < 11 solve for x

kvv77 [185]

Answer:

$\huge \boxed{x < 3}$

Step-by-step explanation:

4x - 1 < 11

Add 1 on both sides.

4x - 1 + 1 < 11 + 1

4x < 12

Divide both sides by 4.

(4x)/4 < 12/4

x < 3

8 0

3 years ago

How do I solve (6^-2)^2 ?

makvit [3.9K]

(6^-2)^2 = 1/1296 = 0.0007716049382716 hope this is what you were looking for. the math is right tho for (6^-2)^2 most calculators can do this easy just do 6^-2 then after just do ^2

8 0

3 years ago

How do I find Trig ratios

nadya68 [22]

Trig ratios can only be used on right triangles with acute measures.

If given an angle and there are adjacent and opposite sides, then use tan(opposite/adjacent)

If given an angle and there is an adjacent side and a hypotenuse, then use cosine(adjacent/hypotenuse)

If given an angle and there is an opposite and adjacent side, then use sin(opposite/hypotenuse)

A common mnemonic device used to memorize the trig rules is SOH-CAH-TOA

8 0

3 years ago