Question

Solve
3x^2= 147
x=
X=

Answer 1

x = 7 or x = -7

Explanation:

First, divide both sides by 3 so we leave with x^2.

`\displaystyle \large{x^2 = (147)/(3) \longrightarrow x^2 = 49}`

Now we have x^2 = 49, remember that we are solving a quadratic equation which means x-values and their counterpart aka negative forms give same output value.

Ex.

2^2 is 4 and (-2)^2 is 4 as well.

3^2 is 9 and (-3)^2 is 9 as well.

Since both positive and negative or counterpart form give same output, when we square both sides, write plus or minus (apply plus or minus when the degree of term is even such as x^2, x^4, x^6, etc.)

Hence,
`\displaystyle \large{√(x^2) = \pm √(49) \longrightarrow x = \pm 7}`

Therefore, x = 7 or x = -7 (you can write x = ± 7 instead)