Question

Thrice the square of a natural number decreased by 4 times the number is equal to 50 more than the number. The number is ?
A) 5
B) 4
C) 7
D) 6

Answer 1

Answer:

A) 5

Step-by-step explanation:

Let the unknown number be x.

so the equation formed will be:

3x²-4x=x+50

3x²-4x-x-50=0

3x²-5x-50=0

If we put the values provided in the options, 5 satisfies the equation.

3*5²-5*5-50 = 3*25-25-50 = 75-25-50 = 0

Answer 2

Given:

Thrice the square of a natural number decreased by 4 times the number is equal to 50 more than the number

To Find:

Find the number

Solution:

Thrice the square of a natural number =$3x^2$

4 times the number =4x

50 more than the number = x+50

We are given that Thrice the square of a natural number decreased by 4 times the number is equal to 50 more than the number

$3x^2-4x=x+50$

$3x^2-5x-50=0$

$(x-5)(3x+10)=0$

$x=5,\frac{-10}{3}$

Since we are given that the number is natural number So, neglect -10/3

Hence The number is 5