To check if the student is correct, we are going to solve the equation step by step.
Step 1 divide both sides of the equation by 5:
Step 2 take square root to both sides of the equation:
or
The equation has tow solutions, and .
I disagree with the student because is just one solution and not the only one; is also a valid solution of the equation.
You would add the 30 to the 40 And then add 45 to that and you will get 112
one column should be added first
General form of equation of circle (1),
(x-h)²+(y-k)²=r²....(1)
h=-f=0
k=-g=0
Cause centre is (-f,-g)or (h,k)
here centre is (0,0)
where r is the radius of the circle,
So the general form of equation o f a circle having centre (0,0) is ,
x²+y²=r²
or,x²+y²-r²=0
Let's say Diana is "x" years old today.
in 3 years, she's going to be " x + 3 " years old.
33 years ago, she was " x - 33 " old.
how much is 4 times that anyway? well 4(x-33), that's 4 times as 33 years ago her age.
now, we know in 3 years, x+3, she'll be "<span>4 times as old as she was 33 years ago", 4(x-33), therefore, those amounts are equal then,
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why is it most logical to use "x" for her age today?
well, because 3 years from now is just x + 3
and
33 years ago is x - 33, 4 times that is 4( x - 33 ).
works very well as a point of reference.</span>