Question

a) 3x3+27=51 b) 64x3+7=8 c) 2x3+300=50 d) 27x3+9=8 e) x(x2+2)=2(x+32) f) x(x2−4)=−4(x+2)

Answer 1

 a) 3x3+27=51
3x3=51-27
3x3=24
x3=24:3
x3=8
x =2

b) 64x3+7=8
64x3=8-7
64x3=1
x3= 1/64
x= 1/4

c) 2x3+300=50
2x3=50-300
2x3= -250
x3= -125
x= -5

d) 27x3+9=8
27x3= -1
x3= -1/27
x= - 1/3

e) x(x2+2)=2(x+32)
x3 + 2x=2x + 64
x3= 2x + 64 - 2x
x3 = 64
x=4

f) x(x2−4)=−4(x+2)
x3 - 4x = -4x - 8
x3 = -4x - 8 + 4x
x3= -8
x= -2