Question

Answer 1

a: =>4(x^2+8x-20)-(x^2+14x+40)=3(x^2+2x-8)

=>4x^2+32x-80-x^2-14x-40=3x^2+6x-24

=>18x-120=6x-24

=>12x=96

=>x=8

b: =>(x+2)^2-16(2x+1)=200+(x-2)^2

=>x^2+4x+4-32x-16=200+x^2-4x+4

=>-28x-12=-4x+204

=>-24x=216

=>x=-9

c: =>3(4x^2-9)=4(x^2-8x+16)+8(x^2-4x+4)

=>4x^2-32x+64+8x^2-32x+32=12x^2-27

=>-64x+96=-27

=>-64x=-27-96=-123

=>x=123/64

d: =>7x^2-14x-5=3(4x^2+4x+1)-5(x^2-2x+1)

=>7x^2-14x-5=12x^2+12x+3-5x^2+10x-5

=>-14x-5=22x-2

=>-36x=3

=>x=-1/12

e: =>7x^2-14x+x-2+4=2x^2-8x+8+5(x^2-4x+3)

=>7x^2-13x+2=2x^2-8x+8+5x^2-20x+15

=>-13x+2=-28x+23

=>15x=21

=>x=7/5