Question

Solve the following quadratic equation.

3(x + 5)^2 = 60

Answer 1

`3(x+5)^2=60\ \ \ |:3\\\\(x+5)^2=20\iff x+5=\pm√(20)\ \ \ |-5\\\\x=-5\pm√(20)\\\\20=4\cdot5\to√(20)=\sqrt4\cdot\sqrt5=2\sqrt5\\\\Answer:\ x=-5-2\sqrt5\ \vee\ x=-5+2\sqrt5`

Answer 2

To solve this equation we could use:

`a^2-b^2=(a+b)(a-b)`

There will be:

`image`