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2 years ago

Hhellp pwease I want to know what's wrong and right

Mathematics

1 answer:

Studentka2010 [4]2 years ago

6 0

Answer:

A: False

B: False

C: True

D: True

E: False

F: True

G: True

H: True

Step-by-step explanation:

A: 9(x - 2) = 9x + 2

9x - 18 = 9x + 2 FALSE

B: 65 - y = y - 65

(equation rearranged) -y + 65 = y - 65 FALSE

C: g (times) h = h (times) g (TRUE due to the commutative property of multiplication)

D: a (times) 0 = 0 (TRUE because anything times 0 equals 0)

E: (4 (times) 2) - r = 4 (2 (times) r)

8 - r = 8 - 4r FALSE

F: k + 0 = k TRUE

G: (a + x) + y = a + (x + y)

a + x + y = a + x + y TRUE

H: 5(2x - 9) = 10x - 45

10x - 45 = 10x - 45 TRUE

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What's the ratio 20:44

Lelechka [254]

This becomes 10:22, then 5:11.

8 0

2 years ago

If sinA=√3-1/2√2,then prove that cos2A=√3/2 prove that

Ivan

Answer:

$\boxed{\sf cos2A =\dfrac{\sqrt3}{2}}$

Step-by-step explanation:

Here we are given that the value of sinA is √3-1/2√2 , and we need to prove that the value of cos2A is √3/2 .

Given :-

• $\sf\implies sinA =\dfrac{\sqrt3-1}{2\sqrt2}$

To Prove :-

• $\sf\implies cos2A =\dfrac{\sqrt3}{2}$

Proof :-

We know that ,

$\sf\implies cos2A = 1 - 2sin^2A$

Therefore , here substituting the value of sinA , we have ,

$\sf\implies cos2A = 1 - 2\bigg( \dfrac{\sqrt3-1}{2\sqrt2}\bigg)^2$

Simplify the whole square ,

$\sf\implies cos2A = 1 -2\times \dfrac{ 3 +1-2\sqrt3}{8}$

Add the numbers in numerator ,

$\sf\implies cos2A = 1-2\times \dfrac{4-2\sqrt3}{8}$

Multiply it by 2 ,

$\sf\implies cos2A = 1 - \dfrac{ 4-2\sqrt3}{4}$

Take out 2 common from the numerator ,

$\sf\implies cos2A = 1-\dfrac{2(2-\sqrt3)}{4}$

Simplify ,

$\sf\implies cos2A = 1 -\dfrac{ 2-\sqrt3}{2}$

Subtract the numbers ,

$\sf\implies cos2A = \dfrac{ 2-2+\sqrt3}{2}$

Simplify,

$\sf\implies \boxed{\pink{\sf cos2A =\dfrac{\sqrt3}{2}} }$

Hence Proved !

8 0

2 years ago

Carys calculates the total amount EEE, in dollars, that she earns for working hhh hours using the equation E=10hE=10hE, equals,

timurjin [86]

Answer:

$10 per hour
0.1 hours

Step-by-step explanation:

To find Carys' earnings in one hour, fill in h=1 in the formula:

E = 10·1 = 10

Carys earns 10 dollars per hour.

To find the number of hours required to earn 1 dollar, fill in E=1 in the formula:

1 = 10h

0.1 = h . . . . . divide by 10

It takes 0.1 hours for Carys to earn 1 dollar.

4 0

3 years ago

Read 2 more answers

1 16

kifflom [539]

Answer:

Step-by-step explanation:

7 0

2 years ago

Ace autos sells cars and pay sue each month

Lena [83]

Sue's total pay of year will have three parts
1) Fixed Salary for 12 months
one month salary = £1410
so 12 month salary = £1410 x 12 = £16920
2) 26% of total profit
Total cost to the company- £473,500
Total income for the company - £549,000
Profit = Total income for the company - Total cost to the company
= £549,000 - £473,500 = £75500
Sues income from profit = 26% of £75500 = (26 × 75500)/100 = £19630
3) Bonus if Sue sells at least 16 cars
Given number of months when sue solds atleast 16 cars = 4
So bonus income = 4 × 390 = £1560
Adding the three above parts
Sue's total pay for the year = £16920 + £19630 + £1560 = £38110

8 0

2 years ago