a) -(3x-5)²-(5x+1)+7=(7x-2)(4x+3)-37x²+15
-(9x²-30x+25)-5x+6=28x²+13x-6-37x²+15
-9x²+25x-19=-9x²+13x+9
25x-13x-19-9=0
12x-28=0
x=28/12
x=7/3
b) 8-(7x+9)²+4x=7x(-7x+3)-3x/4
8-(49x²+126x+81)+4x=-49x²+21x-3x/4
-49x²-122x-73=-49x²+81x/4
-569x/4=73
-569x=292
x=-292/569