Can uh help me in this
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Step-by-step explanation:

b) a² - 1 + b(b - 2a) = a² -1 + b*b -  b*2a     {distributive property}

                              =a² - 1 + b² - 2ab

                               = (a² - 2ab + b² ) - 1  

                               = (a - b)² - 1²           {use identity x²-y²= (x+ y)(x -y)}

                               = (a - b + 1)(a -b +1)

b) 15 +8y + y² - 2x - x² = (y² + 8y  + 15) - x² - 2x

                                    =  (y² + 5y + 3y + 15) - x(x + 2)

                                    = [ y(y + 5) + 3(y +5)] - x(x + 2)

                                   = [(y + 5)(y+3) ] - x(x +2)

all it means is function 3

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4