Maths - Square root / power of 2 question

any number squared is positive but for your calculator you have to include brackets for the equation to make sense. also to explain the quadratic equation confusion just remember two rules - you have to do the same thing on both sides of the equal sign and - do the opposite of the function( ex; if the equation multiplies you must divide to cancel out). so once you factorize it to find "x" you have to divide both side by "x" leaving you with (x- 16)=0 so then add 16 on both sides because it is a subtraction sign not a negative sign and you get the answer x= 16

when she factored x(x-16) you need to make both equal 0
x=0 and x-16=0, add 16 to both sides and you get x=16
actually she told you the wrong answer when she said it is -16
and about the -16^2 thing, yes you automatically assume brackets so then it stays positive
with the exam question, you actually need to put the brackets around 2^2 so that it reads -(2^2)=4

Lol since I'm only 14 but taking 10/11th grade math, it's simple. The first one she was stupid and wrong, the second one she was right;

-2^2 = 4. NOT -4

When you square a negative you're multiplying it by its EXACT self, so

-2 x -2 = 4

When you type -2^2 , your calculator sees this: -(2^2) so it puts the negative aside and just squares the number.

Hope it helped :3

the answer to the last question is x=0 or 16 not -16
a negative number to the power 2 is always positive
(-2)^2=4
-(2^2)=-4


when you plug it into a calculator you should always put in the parentheses just in case

x = 0 , 16 => not -16

Edit:OK,
x^2 + 16x = 0
x = 0 , -16
Check:
(-16)^2 + 16(-16)
= 256 - 256 = 0

If you enter -16^2 => it reads -(16)^2 = -256
But if you enter (-16)^2 = 256

X^2-16X=0................X(X-16)=0......…


+16^2=256........-16^2=256.........-(1…


was that helpful?