Question

Help it's timed.

What are the solution(s) of the quadratic equation 98 – x2 = 0?

x = Plus or minus 2 StartRoot 7 EndRoot
x = Plus or minus 6 StartRoot 3 EndRoot
x = Plus or minus 7 StartRoot 2 EndRoot
no real solution

Answer 1

98 - x² = 0

x² = 98

x = ±√98

Lets factor 98

98 | 2

49 | 7

7 | 7

1

So, 98 = 2 . 7 . 7 = 2 . 7²

x = ±√2.7²

x = ±7√2

Answer 2

`S=\left \{ -7√(2),7√(2) \right \}`

(x = Plus or minus 2 StartRoot 7 EndRoot)

Explanation:

Since b=0, we can simply operate it this way:

`98-x^(2)=0\Rightarrow 98=x^(2)\Rightarrow √(98)=\sqrt{x^(2)}\Rightarrow \sqrt{2*7^(2)}=x\Rightarrow x=\pm 7√(2)\\S=\left \{ -7√(2),7√(2) \right \}`