If 3x-y=27 , 3x+y=243 then find the x value

Correct Answer: 25

Explanation:

a+b=5   ...(1)    and    3a+2b=20 ...(2)

 

Multiplying (1) by 2 and subtracting from (2), we get : a=10.

 

Putting a=10 in (1), we get : b=-5

 

Therefore,   (3a+b) = 3 x 10+(-5)=30-5=25.

Correct Answer: 10 47/60

Explanation:

The given equation is in Mixed fraction.

Now to solve this type of fractions,

$$\begin{gathered} 4 1 3 + 2 1 5 + 4 1 4 = ? \\ ? = 4 + 2 + 4 + 1 3 + 1 5 + 1 4 \\ ? = 10 + 47 60 \\ ? = 10 47 60 \\ \end{gathered}$$

Correct Answer: 1951609

Correct Answer: 19

Explanation:

17 4 7 + 13 2 12 - ? = 11 2 3

123 7 + 158 12 - ? = 35 3

=>  ? = 123 7 + 158 12 - 35 3

=> ? =  1476 + 1106 - 980 84

=> ? = 19.07

Correct Answer: 40

Explanation:

Let ? = p

38 x 7500/100  + p x 375/100 = 50 x 6000/100

=> 38 x 75 + 3.75p = 3000

=> 3.75p = 3000 - 2850

=> p = 150/3.75 

=> p = ? = 40

Correct Answer: 26

Explanation:

Let, Hema attempted 'k' sum correctly, then

k x 3 -2 x(35-k) = 60
5k = 130
k = 26

so 26 correct sums.

Correct Answer: 80578

Explanation:

217 2 + 183 2

 

= 200 + 17 2 + 200 - 17 2

 

It is in the form of  a + b 2 + a - b 2 = 2 a 2 + b 2

 

= 2(40000 + 289) = 80578.

Correct Answer: 10

Explanation:

Let the price of each note book be Rs.x.

Let the number of note books which can be brought for Rs.300 each at a price of Rs.x be y.

Hence xy = 300

=> y = 300/x

(x + 5)(y - 10) = 300 => xy + 5y - 10x - 50 = xy

=>5(300/x) - 10x - 50 = 0 => - 150 + x 2 + 5 x

multiplying both sides by -1/10x

=> x 2 + 15 x - 10 x - 150 = 0

=> x(x + 15) - 10(x + 15) = 0

=> x = 10 or -15

As x>0, x = 10.

Correct Answer: b < 13

Explanation:

The given 3b - 7 < 32 can be solved as

3b - 7 < 32

3b < 39

b < 13.

Correct Answer: 16

Explanation:

given

  48 ? + 32 ? = 320 

=>  6 ? + 4 ? = 40

Now squaring on both sides

=>  36 x ? + 16 x ? + 48 x ? = 1600

=> 100 x ? = 1600

=>  ? = 16