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Aliun [14]
3 years ago
5

Sin78 ×cos42+cos78×sin42 evaluate without the use of a calculator

Mathematics
1 answer:
Novay_Z [31]3 years ago
4 0
Sin a * cos b + cos a * sin b=sin (a+b)

sin 78 * cos 42 + cos 78* sin 42=sin (78+42)=sin 120=sin(180-120)=
sin 60=√3 / 2

Answer: sin 78 * cos 42 + cos 78* sin 42=<span>√3 / 2</span>
You might be interested in
It candy company plans to hang posters of a new product in supermarkets. The product is a box of premium chocolates. The art tea
prohojiy [21]
He answer to this question is:A. The length is 8 inches, and the width is 5 inches.
The scale factor can be found in the question, "the art team made a scale drawing of the top of the box using a scale of 3 inches to 1 inch". This means the scale drawing should be divided by a scale factor of 3:1 (simplified into 3). 
The scale factor is then divided with the components provided (24 inches in length, 15 inches in width).
(24/3) = 8 inches(15/3) = 5 inches
Your answer is length = 8 inches, width = 5 inches.
 hope this helps u
3 0
3 years ago
In 6 years, Mariya will be as old as Vikram is now. In 2 years, Vikram will be three times older than Mariya. Find their ages no
Damm [24]

Answer:

Mariya is 1 year old

Vikram is 7 years old

Step-by-step explanation:

Here, we want to know the present ages of Mariya and Vikram.

Let the present age of Mariya be M and the present age of Vikram be V

From the question, we are told that in 6 years time, Mariya will be as old as Vikram is now

Thus, mathematically;

M + 6 = V ••••••(i)

Furthermore , in 2 years time Vikram will be 3 time older than Mariya

Mathematically;

( V + 2) = 3( M + 2)

V + 2 = 3M + 6

V = 3M + 6-2

V = 3M + 4 •••••••(ii)

So let’s equate the V

3m + 4 = m + 6

3m -m = 6-4

2m = 2

m = 1

But V = m + 6

V = 1 + 6

V = 7

3 0
3 years ago
What is the solution of the system of equations?
umka21 [38]

No solution of the system of equations y = -2x + 5 and -5y = 10x + 20 ⇒ 2nd answer

Step-by-step explanation:

Let us revise the types of solutions of a system of linear equations

  • One solution
  • No solution when the coefficients of x and y in the two equations are equal and the numerical terms are different
  • Infinitely many solutions when the coefficients of x , y and the numerical terms are equal in the two equations

∵ y = -2x + 5

- Add 2x to both sides

∴ 2x + y = 5 ⇒ (1)

∵ -5y = 10x + 20

- Subtract 10x from both sides

∴ -10x - 5y = 20

- Divide both sides by -5

∴ 2x + y = -4 ⇒ (2)

∵ The coefficient of x in equation (1) is 2

∵ The coefficient of x in equation (2) is 2

∴ The coefficients of x in the two equations are equal

∵ The coefficient of y in equation (1) is 1

∵ The coefficient of y in equation (2) is 1

∴ The coefficients of y in the two equations are equal

∵ The numerical term in equation (1) is 5

∵ The numerical term in equation (2) is -4

∴ The numerical terms are different

From the 2nd rule above

∴ No solution of the system of equations

No solution of the system of equations y = -2x + 5 and -5y = 10x + 20

Learn more:

You can learn more about the system of equations in brainly.com/question/6075514

#LearnwithBrainly

7 0
3 years ago
Which expression is equivalent to x 2 - 17x - 60?
creativ13 [48]

Answer:

(x-20)(x+3)

Step-by-step explanation:

6 0
3 years ago
Read 2 more answers
If a car travels three miles in four minutes, find its speed in miles per hour
Butoxors [25]
  • <em>1st divide 4 by 60 to get 15 then 15 x 3 = </em><u><em>45</em></u>
4 0
3 years ago
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