Question

1. twice the square of the sum of a number and 3 is 98.find the number​

Answer 1

Explanation:

Let the number be x.

twice the square of the sum of a number and 3 is expressed as;

2(x+3)²

If the expression is equal to 98, then;

2(x+3)² = 98

divide both sides by 2;

2(x+3)²/2 = 98/2

(x+3)² = 49

square root both sides

√(x+3)² = √49

x+3 = ±7

x = ±7-3

x = 7-3 or -7-3

x = 4 or -10

Hence the number is 4 or -10