Anyone cares to do the math?
It's all bogus, the x^2+16x+64 is possible, it's (x+8)^2, specifically it's factoring a trinomial (to solve it is just find roots of 64, and what adds to be 16, 8, then just put in brackets, (x+8)(x+8), (x+8)^2
They're apparently factoring polynomials, but it's all wrong, just look up any youtube on it
Teaches everything they're apparently doing, including the
(y-4)[(2x-3)(3x+8)] step (which becomes: (y-4)(5x+5) ), which even then, why is their answer in deeper brackets? It's either suppose to be without brackets or be isolated with them
Maybe it's all bogus to seem smart, it's literally hard to understand because it doesn't make any sense
His "cross multiply" is either cross multiply and divide ( 2/3 = x/4 becomes 8/3 = x )
or distributing ( x(y+1)) becomes (xy+x), very basic, "cross" being more than just x, so like (x+y)(z-1) becomes xz-x+yz-y ), but his crossing involves what seems to be the "constant" 1, like how there's always a 1 under a number making it whole, or as a coefficient, or a power, so 1(x/1)^1 is just x, polynomial distribution is more like a Y, not an X of distribution, "cross" doesn't make sense
Main issue is distributing, multiplying polynomials, breaks down brackets, but it looks like no brackets are ever removed, nor does seem to isolate, again, bogus
It even shows a line (to multiply) with 3 and y, but no 3y is ever shown (He's literally saying to multiply 3 to (y+1) to create 3(y+1), come on man(which is then never shown again)), this is apparently the coefficient, 3, to make y+6, really? and no, because it's squared doesn't make any sense, 3^2 is not 6
His "consider" line is bogus, I can't imagine injecting y+6 into a polynomial so casually, it has to come from somewhere, maybe a distribution like 2(y/2+3), he says consider coefficient of x becomes that, but if you're doing that then it has to happen everywhere, and what coefficient? z? you can't make 3 or something become y+6, I've never heard of multiplying the coefficient of a variable with another variable without also distributing the coefficient variable (x)
It looks like it's supposed to be isolating y, and x, and there's two equations which are (supposed to be?) equivalent, which are that: (3x-(2y-3)) and (x+(y+1)) are the same,
substituting say, 1, gives "3" (1+(1+1)) and "4" (3-(2-3))->(3-(-1))->(3+1), not equal
This is the most I could make sense of it, that they're supposed to be equals, because I can't imagine another reason why 2y-3 and y+1 are left like that, they're literally the same variable not factored
The answer's not equal, not isolated, and in deeper brackets, it's all dumb
Anyway, it's stupid like grade 8 math
Edited this, wrote it while tired, missed some brackets