Here are the solutions for each equation:
a) x2+9x+14=0 (x+2)(x+7)=0 x+2=0 or x+7=0 x=−2 or x=−7 b) x2−4x=12 x2−4x−12=0 (x−6)(x+2)=0 x−6=0 or x+2=0 x=6 or x=−2 x2−49=0 (x−7)(x+7)=0 x−7=0 or x+7=0 x=7 or x=−7 d) x2−81=0 (x−9)(x+9)=0 x−9=0 or x+9=0 x=9 or x=−9 e) 9x2−100=0 (3x−10)(3x+10)=0 3x−10=0 or 3x+10=0 3x=10 or 3x=−10 x=310 or x=−310 f) −4x2=−1 x2=41 (2x−1)(2x+1)=0 x=21 or x=−21 g) 3x2−24x=48 3x2−24x−48=0 x2−8x−16=0 This does not factor easily. Let's use the quadratic formula:
x=2a−b±b2−4ac x=2(1)8±(−8)2−4(1)(−16) x=28±64+64 x=28±128 x=28±82 x=4±42 h) 10x2=−19x+15 10x2+19x−15=0 (2x+5)(5x−3)=0 2x+5=0 or 5x−3=0 2x=−5 or 5x=3 x=−25 or x=53 i) −8x2+26x−15=0 8x2−26x+15=0 (4x−3)(2x−5)=0 4x−3=0 or 2x−5=0 4x=3 or 2x=5 x=43 or x=25 j) 2x2−4x=16 2x2−4x−16=0 x2−2x−8=0 (x−4)(x+2)=0 x−4=0 or x+2=0 x=4 or x=−2 k) 3x2=19x−20 3x2−19x+20=0 (3x−4)(x−5)=0 3x−4=0 or x−5=0 3x=4 or x=5 x=34 or x=5 l) 6x2+11x=10 6x2+11x−10=0 (2x+5)(3x−2)=0 2x+5=0 or 3x−2=0 2x=−5 or 3x=2 x=−25 or x=32 m) (x+2)2=4 (x+2)2−4=0 (x+2−2)(x+2+2)=0 x(x+4)=0 x=0 or x+4=0 x=0 or x=−4 n) (x−5)2−9=0 ((x−5)−3)((x−5)+3)=0 (x−8)(x−2)=0 x−8=0 or x−2=0 x=8 or x=2 ñ) 6x2−15x−9=0 2x2−5x−3=0 (2x+1)(x−3)=0 2x+1=0 or x−3=0 2x=−1 or x=3 x=−21 or x=3 o) x2−1=0 (x−1)(x+1)=0 x−1=0 or x+1=0 x=1 or x=−1