What is the standard form of y= (7/5x-4/7)^2+4y=(75x47)2+4?

1 Answer
Oct 2, 2017

y=49/25x^2 -8/5x + 212/49y=4925x285x+21249

Explanation:

Basically you just expand out the bracket.

Rule for squaring things: the first squared, plus the last squared, plus twice the product of the two. (like if you had (x+3)^2(x+3)2 it'd be x^2 + 3^2 + "twice" (3*x) = x^2+6x+9x2+32+twice(3x)=x2+6x+9)

So, (7/5x-4/7)^2(75x47)2 will be (7/5x)^2(75x)2 + (-4/7)^2(47)2 + 2(7/5x*-4/7)2(75x47)
=49/25x^2 + 16/49 -8/5x=4925x2+164985x

Now add the +4:

=49/25x^2 -8/5x + 4 + 16/49 = 49/25x^2 -8/5x +212/49=4925x285x+4+1649=4925x285x+21249